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Sumber: STELA – April 2013. Indeks Storie merupakan metode penilaian (rating) tanah berdasarkan karakteristik tanah yang menentukan potensi pemanfaatan.

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Presentasi berjudul: "Sumber: STELA – April 2013. Indeks Storie merupakan metode penilaian (rating) tanah berdasarkan karakteristik tanah yang menentukan potensi pemanfaatan."— Transcript presentasi:

1 Sumber: STELA – April 2013

2 Indeks Storie merupakan metode penilaian (rating) tanah berdasarkan karakteristik tanah yang menentukan potensi pemanfaatan tanah dan kapasitas produktivitas tanah. Metode ini tidak memperhitungkan faktor fisikj lainnya atau faktor ekonomi yg mungkin mempengaruhi kesesuaian tanaman di suatu lokasi. Analisisnya mudah dilakukan, berbagai kategori dikelompokkan menjadi beberapa kategori saja. SISR: STORIE INDEX SOIL RATINGS

3 Ada empat atau lima parameter yg lazim dievaluasi: A: Kedalaman Tanah dan Tekstur; B: Permeabilitas Tanah; C: Sifat Kimia Tanah; D: Drainage, Limpasan permukaan; E: Iklim (only if it is not homogeneous, if so than it should not be included in the formula); Indeks dihitung dengan perkalian parameter ini, yaitu: S index = A x B x C x D x E Kerugian /kelemahan metode ini adalah kalau kita mempunyai nilai nol untuk suatu kategori, maka hasilnya akan nol dan tanah dianggap tidak sesuai untuk penggunaan. SISR: STORIE INDEX Soil Ratings

4 SISTEM PENILAIAN INDEKS STORIE Sistem ini me-Ranking karakteristik tanah menurut kesesuaiannya untuk pertanian, dari tanah-tanah Grade 1 (nilai ), yg tidak mempunyai pembatas untuk produksi pertanian hingga Tanah-tanah Grade 6 ( nilainya kurang dari 10), yang tidak cocok untuk pertanian. Under this system, soils deemed less than prime can function as prime soils when limitations such as poor drainage, slopes, or soil nutrient deficiencies are partially or entirely removed. The six grades, ranges in index rating, and definition of the grades, as defined by the NRCS, are provided below in Table 3.9, Storie Index Rating System. Sumber: SISR: STORIE INDEX Soil Ratings

5 Indesk Storie merupakan metode semi-kuantitatif penilaian tanah yg dapat digunakan untuk pertanian irigasi berdasarkan data produktivitas tanaman yang dikumpulkan dari survei tanah (Storie 1932; Reganold and Singer 1979). Indeks Storie menduga produktivitas tanah berdasarkan empat karakteristik berikut: 1.Factor A: Derajat perkembangan profil tanah; 2.Factor B: Tekstur lapisan permukaan; 3.Factor C: Slope; 4.Factor X: Kondisi lain tanah dan lahan, termasuk drainage, alkalinity, fertility, acidity, erosion, dan microrelief. Sumber: SISR: STORIE INDEX Soil Ratings

6 Skor berkisar % ditentukan untuk setiap faktor, dan skor-skor ini kemudian dikalikan satu-sama lain untuk mendapatkan Nilai Indeks (Storie 1978). One shortcoming of hand-generated Storie ratings is that the scoring options for a particular factor or subfactor have broad and somewhat arbitrary ranges, which creates a great potential for subjectivity among scientists (O’Geen and Southard 2005). Our goal was to develop a model in NASIS to rapidly generate Storie ratings without inherent scoring discrepancies associated with hand- generated ratings. Nilai Indeks Storie = [(Factor A/100) × (Factor B/100) × (Factor C/100) × (Factor X/100)] × 100 Sumber: SISR: STORIE INDEX Soil Ratings

7 Storie Index Rating System Sumber: REVISI SISR: STORIE INDEX Soil Ratings GradeNilai IndeksDefinisi 1 – Excellent80 – 100Tanah-tanah sangat sesuai untuk penggunaan intensif tanaman irigasi yang sesuai dnegan kondisi iklimnya. 2 – Good Tanah-tanah sesuai untuk pertanian, although they may not be so desirable as Grade 1 because of moderately coarse, coarse, or gravelly surface soil texture; somewhat less permeable subsoil; lower plant available water holding capacity, fair fertility; less well drained conditions, or slight to moderate flood hazards, all acting separately or in combination. 3 – Fair Tanah-tanah cukup sesuai untuk penggunaan pertanian secara umum, and are limited in their use because of moderate slopes; moderate soils depths; less permeable subsoil; fine, moderately fine or gravelly surface soil textures; poor drainage; moderate flood hazards; or fair to poor fertility levels, all acting alone or in combination.

8 Storie Index Rating System Sumber: REVISI SISR: STORIE INDEX Soil Ratings GradeIndex Rating Definisi 4 – Poor Tanah-tanah kurang sesuai. They are severely limited in their agricultural potential because of shallow soil depths; less permeable subsoil; steeper slope; or more clayey or gravelly surface soil texture than Grade 3 soils, as well as poor drainage; greater flood hazards; hummocky micro-relief; salinity; or poor fertility levels, all acting alone or in combination. 5 – Very Poor Tanah-tanah secara aktual tidak sesuai untuk pertanian, jarang diolah untuk pertanian, biasanya untuk range, pasture, atau hutan. 6 – Non- agricul- ture Kurang dari 10 Soils are not suited for agriculture at all due to very severe to extreme physical limitations, or because of urbanization. Source: USDA Soil Conservation Service, Soil Survey of Contra Costa County, 1977.

9 Semenjak 1980, negara bagian California telah melakukan pemetaan lahan-lahan pertaniannya. Program pemetaan lahan pertanian ini dilakukan secara terus- menerus dengan tingkat pemetaan yang semakin detail. Kkriteria pemetaan lahan juga dimodifikasi terus menjadi semakin detail. Kriteria pemetaan lahan menggunakan sistem Indeks Storie dan sistem SCS (konservasi tanah), tetapi juga mempertimbangkan kondisi fisik seperti suplai air untuk produksi tanaman, soil temperature range, depth of the ground water table, flooding potential, rock fragment content and rooting depth. Sumber: SISR: STORIE INDEX Soil Ratings

10 Important Farmland Maps for California are compiled using the modified LIM criteria (as described above) and current land use information. The minimum mapping unit is 10 acres unless otherwise specified. Unit-unit lahan yng kurang dari 10 acre dimasukkan ke dalam klasifikasi unit-lahan di sekitarnya. Peta lahan pertanian mengidentifikasi tujuh kategori yg berhubungan dg pertanian: Prime farmland, farmland of statewide importance (statewide farmland), unique farmland, Lahan pertanian lainnya yg penting secara lokal. Each is summarized below, based on A Guide to Farmland Mapping and Monitoring Program (1998), prepared by the Department of Conservation. Sumber: SISR: STORIE INDEX Soil Ratings

11 Arahan untuk pemetaan lahan pertanian yang disusun oleh Departemen Konservasi USDA (1998). Sumber: SISR: STORIE INDEX Soil Ratings Prime Farmland: Prime farmland is land with the best combination of physical and chemical features able to sustain the long-term production of agricultural crops. This land has the soil quality, growing season, and moisture supply needed to produce sustained high yields. The land must have been used for the production of irrigated crops at some time during the two update cycles (a cycle is equivalent to 2 years) prior to the mapping date of 1998 (or since 1994). Statewide Farmland: Farmland of Statewide Importance is land similar to prime farmland, but with minor shortcomings, such as greater slopes or with less ability to hold and store moisture. The land must have been used for the production or irrigated crops at sometime during the two update cycles prior to the mapping date (or since 1994). Unique Farmland: Unique farmland is land of lesser quality soils used for the production of the State’s leading agricultural crops. This land is usually irrigated, but may include non-irrigated orchards or vineyards, as found in some climatic zones in California. The land must have been cultivated at some time during the two update cycles prior to the mapping date (or since 1994).

12 Sumber: SISR: STORIE INDEX Soil Ratings Local Farmland: Farmland of local importance is land of importance to the local agricultural economy, as determined by each county’s Board of Supervisors and a local advisory committee. Contra Costa County local farmland includes lands which do not qualify as Prime, Statewide, or Unique designation, but are currently irrigated crops or pasture or non-irrigated crops; lands that would meet the Prime or Statewide designation and have been improved for irrigation, but are now idle; and lands that currently support confined livestock, poultry operations and aquaculture. Grazing Land: Grazing land is land on which the existing vegetation, whether grown naturally or through management, is suited to the grazing of livestock. The minimum mapping unit for this category is 40 acres. Arahan untuk pemetaan lahan pertanian yang disusun oleh Departemen Konservasi USDA (1998).

13 Sumber: SISR: STORIE INDEX Soil Ratings Urban Land: Urban and built-up land is occupied with structures with a building density of at least one unit to onehalf acre. Uses may include but are not limited to, residential, industrial, commercial, construction, institutional, public administration purposes, railroad yards, cemeteries, airports, golf courses, sanitary landfills, sewage treatment plants, water control structures, and other development purposes. Highways, railroads, and other transportation facilities are mapped as part of this unit, if they are part of a surrounding urban area. Other Land:Other land is land that is not included in any other mapping categories. The following uses are generally included: rural development, brush timber, government land, strip mines, borrow pits, and a variety of other rural land uses. Arahan untuk pemetaan lahan pertanian yang disusun oleh Departemen Konservasi USDA (1998).

14 R. Earl Storie is Professor Emeritus, Soils and Plant Nutrition and former Soil Technologist in the Experiment Station, Berkeley. INDEKS STORIE Metode penilaian tanah ini, dikenal sebagai Indeks Storie, berdasarkan atas karakteristik tanah yg mengendalikan pemanfaatan lahan dan kapasitas produktif lahan. It is independent of other physical or economic factors that might determine the desirability of growing certain plants in a given location. Sumber: SISR: STORIE INDEX Soil Ratings

15 Metode Storie yang telah direvisi menetapkan Faktor-C yang baru untuk mengevaluasi slope; Faktor-C yang lama sekaranh dimasukkan ke dalam Faktor-X. Nilai-nilai persentase diberikan pada karakteristik tanah, termasuk Profil Tanah (faktor A); Tekstur tanah permukaan (faktor B); Slope (faktor C); Dan kondisi-kondisi yg eksklusif profil tanah, tekstur permukaan, dan slope – misalnya drainage, kandungan alkali, kandungan hara, erosion, dan micro relief (factor X). Kondisi yang dianggap paling ideal (paling sesuai) untuk setiap faktor diberi nilai 100%. Nilai-nilai persentase dari empat faktor itu kemudian dikalikan bersama untuk menghasilkan Nilai Indeks Storie dari tanah yang dievaluasi. Sumber: SISR: STORIE INDEX Soil Ratings

16 Karakteristik profil tanah (faktor A) pada hakekatnya merupakan ciri-ciri lapisan bawah permukaan. Tanah di lokasi survei (mis. Di California) dikelompokkan menjadi beberapa kelompok profil (mis. ada 9 kelompok profil tanah). For example, soils that are deep and readily pervious to roots and water (listed in profile group I in the soil-rating chart) are rated at 100 percent. Profil tanah dengan subsoil liat-padat (Kelompok Profil IV) diberi nilai lebih rendah. Primary or residual soils (listed in profile groups VII, VIII, and IX) are rated in accordance with the depth to bedrock. Sumber: SISR: STORIE INDEX Soil Ratings

17 Tanah-tanah dinilai berdasarkan tekstur tanah lapisan permukaan (Faktor B). Medium- textured soils, such as the loams and the silt loams, are rated highest; the extremes in texture, such as sands and clays, lower. Penilaian kemiringan lahan dimasukkan dalam Faktor C. Nearly level or gently sloping land is rated at 100 per cent. As the slope increases, the rating for this factor decreases. As shown in the soil-rating chart, single letters are used to indicate simple slopes, and double letters to indicate compound slopes. The percent slope expresses the number of feet rise or fall for 100 feet horizontal distance. Sumber: SISR: STORIE INDEX Soil Ratings

18 Kondisi eksklusif profil, tekstur tanah, dan slope dimasukkan dalam Faktor X pada peta penilaian tanah. These conditions consist of drainage, alkali or salt content, general nutrient level, acidity, erosion, and microrelief (surface regularity). If two or more conditions exist that are listed under factor X, the ratings for each are treated independently; that is, they are multiplied in order to secure the factor X rating. Sumber: SISR: STORIE INDEX Soil Ratings

19 SOIL - RATING CHART (Storie Soil Index rating = factor A x factor B x factor C x factor X) Sumber: SISR: STORIE INDEX Soil Ratings

20 Faktor A: Kelompok Profil Tanah Faktor A adalah nilai karakteristik profil tanah berdasarkan derajat perkembangan tanah. Tanah-tanah dikelompokkan ke dalam “Kelompok Profil” berdasarkan tipe landform dan perkembangan horison genetiknya. Soil development is defined as the presence of Bt horizons or cemented layers. Bt horizons are subsurface layers that have an increase in clay relative to the overlaying horizons. The increase is a result of the translocation of clay by percolating water from overlaying soil horizons. Sumber: SISR: STORIE INDEX Soil Ratings

21 Faktor A: Kelompok Profil Tanah Untuk tanah-tanah alluvial, skor-nya semakin menurun dengan semakin meningkatnya derajat perkembangan tanah, seperti yang ditunjukkan oelh adanya horison Bt dan/atau adanya lapisan penghambat pertumbuhan akar. Misalnya, tanah-tanah aluvial yang solumnya dalam dan homogen diberi nilai 100%, sedangkan tanah-tanah yang mempunyai horison Bt pada landsekap-tua diberi nilai lebih rendah. Soils with abrupt textural changes (claypan), duripan, or petrocalcic horizons (hardpans) are rated lower still. For soils derived from bedrock, scoring is based on depth to a lithic (hard rock) or paralithic (soft rock) contact and the degree of soil development in horizons overlying these layers (Storie 1932, 1978). Sumber: SISR: STORIE INDEX Soil Ratings

22 Faktor B: Tekstur Tanah Lapisan Permukaan Faktor B berdasarkan tekstur tanah lapisan atas. Tanah-tanah berlempung mempunyai nilai paling tinggi, dan tanah-tanah liat tan tanah berpasir dinilai lebih rendah. Rock fragment content is used to modify the scores, which range from 100 to 10%. The rating for Factor B can vary as much as 30% for a specific textural class depending on the volume of coarse fragments present (Storie 1932, 1978). Sumber: SISR: STORIE INDEX Soil Ratings

23 Faktor C: Slope Faktor C berdasarkan pada kecuraman lereng. Lahan yang hampir datar hingga sedikit miring (0 - 8% slope) diberi nilai tinggi, berkisar %. Moderate to strongly sloping conditions (9 to 30% slopes) have scores ranging from 95 to 70%; slopes greater than 30% receive lower scores, ranging from 50 to 5% (Storie 1978). Users choose a score in a somewhat subjective manner based on these slope classes. Sumber: SISR: STORIE INDEX Soil Ratings

24 Faktor X: Drainage, Alkalinity, Fertility, Kemasaman, Erosi, dan Microrelief Faktor X fokus pada sifat-sifat dinamis, kondisi tanah dan landskap yg memerlukan pengelolaan secara khusus. Characteristics considered are drainage class, alkalinity, nutrient status, degree of acidity, wind and water erosion, and microrelief. Scoring for each characteristic in Factor X is subjective. For example, drainage, erosion, and microrelief scores range from 100 to 10%, while fertility status and acidity scores range from 100 to 60 and 95 to 80%, respectively (Storie 1978) Sumber: SISR: STORIE INDEX Soil Ratings

25 PERKEMBANGAN MODEL In our NASIS-based Storie Index, interpretation criteria were modeled based on soil properties traditionally incorporated into the hand- generated Storie Index (1978). The most closely related NASIS data elements that pertained to the Storie 1978 criteria were used. Our model uses discrete and fuzzy logic functions to obtain more precise scores for the factors associated with the index. Banyak kriteria baru dimasukkan ke dalam Model, dan faktor lainnya dimodifikasi untuk menyesuaikan indeks dengan basis-data yang tersedia. Model Storie 1978 telah mengalami beberapa modifikasi dalam penerapannya hingga saat ini. Sumber: Rivised SISR: STORIE INDEX Soil Ratings

26 A system of interpretation generation using fuzzy logic was included within the database structure during NASIS development in order to develop more realistic soil interpretations. Our model uses fuzzy rule sets to more accurately score Factors C and X. Discrete numerical scores in combination with fuzzy logic functions were used for Factors A and B. Gelisols, Histosols, Spodosols, Oxisols, Dan Andisols tidak dapat dievaluasi, karena tanah-tanah ini tidak dikenal dalam referensi Storie Sumber: Rivised SISR: STORIE INDEX Soil Ratings

27 Faktor A: Kelompok Profil Tanah Banyaknya kelompok profil tanah untuk Faktor A diubah dari sembilan kelompok dalam Storie 1978 menjadi empat kelompok. Kelompok profil dalam Storie 1978 mengklasifikasikan tanah berdasarkan derajat perkembanagannya dan sifat bahan induknya. Dalam Model revisi ini ada penggabungan kelompokn profil tanah yang kisaran skor-nya hampir sama. Interpretive criteria implied in Storie Profile Group Factor A relied on the current taxonomic placement (USDA NRCS 1999) of the soil in NASIS. Thus, in some instances, out-of-date classifications needed to be considered (table 1). Variations on the profile group fuzzy rating curves (slope and shape) that modify the effective rooting depth were devised to best match the original scoring in Storie Sumber: Rivised SISR: STORIE INDEX Soil Ratings

28 Tahap pertama dalam pemodelan adalah memilahkan tanah-tanah yang berkembang dari batuan induk (Groups VI - IX) dari tanah- tanah yg berkembang dari bahan aluvial (Group I - V). Landform type, a data field stored in NASIS, was used for this initial classification. Sumber: Rivised SISR: STORIE INDEX Soil Ratings

29 Groups I to III of Storie 1978 were combined because they have a similar scoring range and reflect subtle differences in soil development. These soils, which are found on alluvial deposits, are scored based on the depth to root-restricting layers such as shallow phases, consolidated material, gravel lenses, and stratified layers with texture contrasts. The scoring differences are identical in Groups I and II of Storie 1978 and are only slightly lower in Group III. For these reasons they were combined in our model. The soils of Groups I to III were identified through their classification. Pada umumnya semua tanah-tanah Entisols, Inceptisols, Vertisols, Aridisols, Alfisols, Mollisols, dan Ultisols yang tidak menunjukkan peningkatan kandungan liat secara drastis dengan kedalaman atautidak mempunyai lapisan keras, dimasukkan dalam Model. A “more is better” fuzzy rating was applied to these profiles in reference to depth to a restrictive layer. The curve reflects an optimal effective rooting depth where soil thicknesses that exceed 100 centimeters received a maximum score of 100. Skor-skor dikurangi berdasartkan kedalaman lapisan penghambat pertumbuhan akar. Sumber: Rivised SISR: STORIE INDEX Soil Ratings

30 Index Storie yang diaplikasikan dalam Model NASIS Factor A Soil profile group (see figure 2 and table 1) Landform Mulai Factor B Surface texture Groups I-III Soil Orders: Entisols, Vertisols, Aridisols, Alfisols, Mollisols, Ultisols, Inceptisols Groups VII-IX Soil depth: Fuzzy rule - “more is better” Soil orders not rated: Histosols, Gelisols, Spodosols, Oxisols, and Andisols Groups IV Soil with abrupt clay increase: “Pale” Groups V Soil with cemented layers: Petrocalcic Duripan Crisp limits for surface textural class scores (see table 2) Fuzzy rule - “less is better” for surface coarse fragments (see figure 3) X X Fans, terraces, and flood plains Uplands Scores determined by effective soil depth using fuzzy rule

31 X Factor C Slope Fuzzy rule - “less is better” Slope 0-100% (see figure 4) Factor X Dynamic properties X Hydrology and Physical properties Chemistry and fertility X Growing season wetness - “less is better” (see figure 6) Flooding - fuzzy rule “less is better” (see figure 7 and table 5) Erosion - crisp limits (see table 4) Drainage - crisp limits (see table 3) EC - fuzzy rule “less is better” (see figure 5b) SAR - fuzzy rule “less is better” (see figure 5b) pH - fuzzy rule “optimum ” (see figure 5a) Index Storie yang diaplikasikan dalam Model NASIS

32 Konsep awal tentang Profil Kelompok IV dalam Storie 1978 tetap digunakan dalam Model ini. Soils in this group are found on older plains and terraces and have dense, clay-rich subsoils that restrict the movement of water and roots. Soils in this group were identified in NASIS based on Soil Taxonomy (USDA NRCS 1999). All soils with the formative element “pale” at the great group level were included. In addition, Albaqualfs and Albaquults were included. The upper limit of the scoring range for Profile Group IV in Storie 1978 was initially assigned, then modified by effective soil depth. Misalnya, tanah Palexeralf (tanah dengan lapisan cadas liat) dengan kedalaman cadas liat kurang dari 1 foot semestinya akan mendapat nilai 85. Skor ini kemudian direvisi berdasarkan “kedalaman yang tepat” hingga horison (lapisan) penghambat akar. Hal ini menghasilkan skor Faktor A yang lebih rendah untuk tanah Palexeralf (~35) berdasarkan tebalnya lapisan tanah di atas lapisan cadas liat. Sumber: Rivised SISR: STORIE INDEX Soil Ratings

33 Konsep original Kelompoik Profil V tetap dipertahankan dalam Model ini. Tanah-tanah dalam kelompok ini ditemukan pada kipas dan terras tua, dan mempunyai subsoil yang padat dan keras, sehingga membatasi pergerakan air dan pertumbuhan akar. Semua tanah dengan anasir formatif Duri, Petro, Fragi, Petra, dan Plinth yang muncul pada tingkat great-group juga dimasukkan dalam model. Semua tanah Durids yg diklasifikasikan pada tingkat suborder dan tanah-tanah Duric atau Petrogypsic pada tingkat subgroup juga dimasukkan dalam Model. The upper limit of the scoring range for Profile Group V in Storie 1978 was initially assigned. A fuzzy logic rule “more is better,” in reference to depth to the cemented pan, was then used to revise the upper limit of the score based on the exact depth (the representative value for depth in NASIS) to the restrictive horizon. Sumber: Rivised SISR: STORIE INDEX Soil Ratings

34 Formative elements of restrictive horizons are not used at the great group level in Soil Taxonomy (1999) where the upper boundary of the layer is greater than 1 meter below the surface. In such cases, the depth to these layers is populated in NASIS as a component restriction in the database. A “flag” was placed in the model so that when the component restriction attribute is populated the soil is placed in its appropriate profile group and scored accordingly. Sumber: Rivised SISR: STORIE INDEX Soil Ratings

35 Group VI dalam sistem Storie 1978 dihilangkan karena kesamaannya dengan Group IV. Group VII hingga IX dalam Storie 1978 digabungkan karena mereka mempunyai kesamaan kisaran skor berdasarkan kedalaman perakaran. Kelompok ini mencerminkan tanah- tanah dengan bahan induk residuum dan colluvium. The fuzzy logic rule “more is better,” in reference to depth to lithic or paralithic contact, was used to modify the score based on the rooting depth. Sumber: Rivised SISR: STORIE INDEX Soil Ratings

36 Faktor B: Tekstur lapisan permukaan Nilai-nilai Crisp ditetapkan untuk kelas tekstur tanah lapisan permukaan sesuai dengan Storie 1978 (Table 2). The following textures were not listed in Storie 1978: very fine sandy loam, sandy clay, loamy coarse sand, loamy fine sand, loamy very fine sand, and silt. These missing textural classes were assigned ratings in our model (Table 2). At the present time, the NASIS model does not rank organic horizons. Sumber: Rivised SISR: STORIE INDEX Soil Ratings

37 Faktor B: Tekstur lapisan permukaan Semua skor kelas tekstur tanah dimodifikasi berdasarkan kandungannya fragmen batuan dengan menerapkan aturan logika- fuzzy “less is better”. The slope of line segments differed based on three coarse fragment volume classes: less than 15%, 15 to 35%, and greater than or equal to 35%. The fuzzy score for rock fragment content was then used to weight the surface soil textural class score for Factor B. For example, a silt loam with 5% rock fragments received a score of 100%, while a very gravelly silt loam with 40% rock fragments received a score of approximately 60%, that is, it was weighted proportionally to the volume of coarse fragments present. Sumber: Rivised SISR: STORIE INDEX Soil Ratings

38 Faktor C: Slope The scoring threshold values for slope classes established in Storie 1978 were used to append the fuzzy logic rule “less is better” to produce a unique score for any representative value of slope stored in NASIS. Fungsi ini mengurangi subyektivitas yg berhubungan dengan pemilihan suatu skor dari kisaran skor-skor di dalam setiap faktor. Misalnya dalam Storie 1978 : Faktor C (slope) mempunyai kategori slope dengan skor yang berkisar dari 100% (“nearly level”) hingga 5% (“very steep”). Sumber: Rivised SISR: STORIE INDEX Soil Ratings

39 Faktor X: Sifat-sifat yang Dinamik Data elements stored in NASIS that pertain to Factor X (renamed “Dynamic Properties” in our model) were combined into two groups: chemical and fertility properties (Xcf); and hydrologic and physical conditions (Xhp). Soil chemical and fertility limitations were established for pH, electrical conductivity (EC), and sodium adsorption ratio (SAR). Hydrologic and physical conditions were assessed using drainage class, flooding frequency, flooding duration during the growing season, saturated conditions during the growing season, and erosion class. The Factor X score was calculated as the product of the lowest score in each subfactor group (Xcf and Xhp). Dalam Model ini, hanya digunakan dua sifat dinamis yang paling membatasi untuk perhitungan Faktor X. Xcf x Xhp = Faktor X dimana: Xcf : Skor terendah dari subfaktor kimia dan kesuburan Xhp : Skor terendah subfaktor kondisi hydrologis dan fisika. Sumber: Rivised SISR: STORIE INDEX Soil Ratings

40 Kondisi kimiawi pada Faktor X yang telah direvisi agak berbeda dengan faktor X dalam Storie In order to obtain more quantitative indices for chemical conditions in soil, thresholds in toxicity or osmotic effects were established for electrical conductivity (EC) and pH to reflect conditions that adversely affect plant growth, as well as for sodium adsorption ratio (SAR) to reflect conditions that affect soil dispersion and water movement. Tanah-tanah mendapatkan nilai 100% hingga tercapai tingkat sub- optimal. Sumber: Rivised SISR: STORIE INDEX Soil Ratings

41 Fuzzy rule sets were implemented in NASIS to model the magnitude of the impairment. For example, an optimal curve was used to score pH through a trapezoidal pH optimal curve reflecting extremes in alkalinity and acidity. Scores of 100% were given to pH values ranging from 5.5 to 8.5. A “less is better” curve was used to score SAR and EC. Scores begin to decrease with SAR values that exceed 7. Soil Taxonomy (1999) uses SAR greater than or equal to 13 to indicate Na-affected soils, but other research has shown that soil water movement can be affected by Na dispersion at SAR as low as 5 (Shainberg et al. 1981). Scores begin to decrease when EC is greater than 1 and then decrease sharply when the threshold for saline soils (EC ≥ 4 dSm-1 ) is surpassed (Regional Salinity Laboratory Staff 1954). Sumber: Rivised SISR: STORIE INDEX Soil Ratings

42 Crisp scores were assigned to certain soil physical properties because many are interpretations reported as classes rather than measured continuous variables. Scores for drainage class and erosion class were derived using crisp values (Tables 3 and 4). Scores for a particular erosion class were higher for uplands because slope is a component of the erosion class. Also, because slope was already considered in Factor C, these scores were adjusted to avoid penalizing the site twice for the same condition. Uplands versus lowlands were identified in NASIS based on landform type and scored separately. Sumber: Rivised SISR: STORIE INDEX Soil Ratings

43 Tanah jenuh air, frekuensi banjir, dan durasi banjir berpengaruh buruk terhadap pertumbuhan tanaman kalau terjadi selama musim pertumbuhan tanaman. Lamanya musim pertumbuhan ditentukan berdasarkan regim suhu tanah. Tanah- tanah dnegan resim suhu cryic, pergelic, atau isofrigid mempunyai musim pertumbuhan lebih pendek, July dan August. Soils with frigid or mesic temperature regimes were given a growing a season from May to September, while thermic temperature regimes were given a growing season from March to October. Isomesic and hyperthermic regimes were given growing seasons that extended 11 months of the year, from February through December. Isothermic and isohyperthermic temperature regimes had year-round growing seasons. The minimum depth to saturated conditions encountered during the growing season was derived from the fuzzy logic curve “more is better” (fig. 6). Flooding (duration and frequency) was also assessed according to these defined growing seasons. Sumber: Rivised SISR: STORIE INDEX Soil Ratings

44 Interpretasi survei tanah ttg kelas frekuensi banjir dan kelas durasi banjir digunakan untuk mendeskripsikan dampak kejadian banjir yg terjadi selama musim pertumbuhan tanaman. Flooding frequency is an estimate of the number of flood events that occur in a month. Flooding duration is the length of time flood waters reside on a particular site. Scores were established for flooding duration and frequency classes that are reported in NASIS. The scores for a particular flooding duration class and flooding frequency class were then multiplied to get a flooding frequency and duration factor for the growing season. Hubungan linear digunakan untuk merevisi skor bagi sub-faktor ini. Sumber: RIVISED SISR: STORIE INDEX SOIL RATINGS

45 Keuntungan Pendekatan Pemodelan Indeks Storie Indeks Storie yang direvisi mencerminkan penyempurnaan dari sistem klasifikasi Indeks yang dihitung dengan Model NASIS ini snagat cepat, tidak bias, dan akurat untuk menilai potensi produktivitas lahan di daerah survei. It is capable of generating hundreds of Storie ratings in seconds for SSURGO II datasets. The NASIS model is a data-driven tool that reduces the subjectivity of the hand-generated Storie Index and improves the reliability of these ratings, which may guide land use policy for the future. Sumber: Rivised SISR: STORIE INDEX Soil Ratings

46 Keuntungan Pendekatan Pemodelan Indeks Storie Model ini berbeda dengan Storie 1978 karena beberapa sifat tanah dan landskap disimpan dalam basis-data NASIS. Perubahan juga dilakukan untuk meningkatkan objektivitas skoring. For Factor A, profile groups were condensed from nine in Storie 1978 to four because the range in scores was similar in some groups (Profile Groups I to III and VII to IX). We also eliminated Profile Group VI in Storie 1978 because of its similarity to Group IV. Sumber: Rivised SISR: STORIE INDEX Soil Ratings

47 Keuntungan Pendekatan Modeling Indeks Storie Modifikasi dilakukan pada Faktor X, yang disebut “Faktor Dinamik.” Dalam Model Storie 1978 digunakan kondisi-alkali, tetapi dalamk Model ini digunakan nilai-nilai EC dan SAR untuk mencerminkan kondisi-kondisi saline, sodik, dan saline- sodik. An assessment of nutrient status was not attempted in our model because fertility can be a very dynamic property in agricultural settings, depending on fertilization practices and other variables. Flooding frequency and duration of saturation during the growing season were added to Factor X because of their importance in assessing land capability. Microrelief was not used in our model because it is often not populated in NASIS (especially in older surveys) and because land leveling has altered most agricultural land that once contained microrelief Sumber: Rivised SISR: STORIE INDEX SOIL RATINGS

48 Kurva rating linear untuk interaksi banjir, dihitung fengan menggunakan skor frekuensi banjir dan skor lamanya (durasi) banjir, sbb: Flooding interaction = (frequency class/100) x (duration class/100). Sumber: Rivised SISR: STORIE INDEX Soil Ratings

49 Table 5. Subfactor scores for Factor X, flooding frequency* and duration during the growing season. Note: Flooding frequency and duration classes are defined in the National Soil Survey Handbook (USDA NRCS 2007). Sumber: Rivised SISR: STORIE INDEX Soil Ratings Kelas Frekuensi Banjir Skor Kelas Durasi Banjir Skor None100None100 very rare100extremely brief100 Rare90very brief100 Occasional85brief95 Frequent70long85 very frequent60very long75

50 Figure 6. “Optimal: more is better” fuzzy rating curve for Factor X, depth to saturation during the growing season. Sumber: Rivised SISR: STORIE INDEX Soil Ratings

51 Table 4. Skor Subfaktor untuk Faktor X, Kelas Erosi. (Erosion ratings were different for uplands versus lowlands because slope is a dominant variable impacting erosion class ratings in uplands.) Sumber: Rivised SISR: STORIE INDEX Soil Ratings Kelas ErosiSkore Lowland Skore Upland

52 Tabel 3. Skor Subfaktor untuk Faktor X, Kelas Drainage Sumber: Rivised SISR: STORIE INDEX Soil Ratings Kelas DrainageSkor Excessively drained and Somewhat excessively drained85 Well drained100 Moderately well drained90 Somewhat poorly drained70 Poorly drained and very poorly drained50

53 Table 1. Faktor A, penyebutan kelompok profil tanah melalui data taxonomi yg disimpan dalam NASIS (Note: Landform type, a field stored in NASIS, was first used to separate alluvial soils (Groups I to V) from upland soils (Groups VI to IX). Soil Taxonomy (USDA NRCS 1999) was used to place the soil in one of four new groups. Histosols (peat soils), Gelisols (soils with permafrost), Oxisols (highly weathered tropical soils), Andisols (volcanic soils), and Spodosols (cool humid forest soils) were not rated. Sumber: Rivised SISR: STORIE INDEX Soil Ratings Storie 1978 profile group Revised profile group Taxonomic units queriedConcept notes and query rules I1Suborders: Fluvents, Aquents, Psamments, Orthents, Xererts, Torrerts, Usterts, Uderts Great groups: Haplaquolls, Aquisalids, Calciaquerts, Dystraquerts, Epiaquerts Endoaquerts, Natraquerts, Salaquerts Subgroups: Calcic Haplosalids, Gypsic Haplosalids, Typic Haplosalids Soils of recent alluvial deposits. Query rules: Must not have restrictive horizons and cannot be on hillslopes or mountains.

54 Table 1. Faktor A, penyebutan kelompok profil tanah melalui data taxonomi yg disimpan dalam NASIS Sumber: Rivised SISR: STORIE INDEX Soil Ratings Storie 1978 profile group Revised profile group Taxonomic units queriedConcept notes and query rules II1Suborders: Arents, Cambids Great groups: Haploxerolls, Haplustolls, Hapludolls, Vermustolls, Calciustolls, Haprendolls, Calciudolls, Vermudolls, Calciaquolls, Calcigypsids, Haplogypsids, Haplocalcids, Sulfaquepts, Vermaquepts, Endoaquepts, Epiaquepts, Humaquepts, Sulfudepts, Eutrudepts, Dystrudepts, Calciustepts, Dystrustepts, Haplustepts, Calcixerepts, Haploxerepts Outdated taxa: Xerumbrepts and Xerochrepts Young soils on alluvial deposits. Query rules: Cannot be on hillslopes or mountains. Outdated taxa included if updates were not performed in NASIS. Presence of abrupt textural change included for stratified soils and gravelly subsoils.

55 Table 1. Faktor A, penyebutan kelompok profil tanah melalui data taxonomi yg disimpan dalam NASIS Sumber: Rivised SISR: STORIE INDEX Soil Ratings Storie 1978 profile group Revised profile group Taxonomic units queriedConcept notes and query rules III1 Great groups: Argigypsids, Natrigypsids, Natrargids, Gypsiargids, Calciargids, Haplargids, Vermaqualfs, Epiaqualfs, Endoaqualfs, Glossaqualfs, Kandiaqualfs, Natraqualfs, Hapudalfs, Kandiudalfs, Kanhapludalfs, Natrudalfs, Haplustalfs, Rhodustalfs, Natrustalfs,Natrixeralfs, Rhodoxeralfs, Haploxeralfs, Argialbolls, Natralbolls, Natraquolls, Argiaquolls, Natrudolls, Argiudolls, Natrustolls, Argiustolls, Natrixerolls, Argixerolls, Kandiaquults, Kanhaplaquults, Umbraquults, Endoaquults, Epiaquults, Kandihumults, Kanhaplohumults, Haplohumults, Kandiudults, Kanhapludults, Hapludults, Rhodudults, Kandiustults, Kanhapustults, Rhodustults, Haplustults, Haploxerults; also includes all “pale” great groups and Albaqualfs and Albaquults that do not have an abrupt clay increase with depth, but may have a thick argillic Moderately well- developed soils formed in older alluvial deposits. Query rules: Cannot be on hillslopes or mountains. Presence of abrupt textural change included for stratified soils and gravelly subsoils.

56 Table 1. Faktor A, penyebutan kelompok profil tanah melalui data taxonomi yg disimpan dalam NASIS Sumber: Rivised SISR: STORIE INDEX Soil Ratings Storie 1978 profile group Revised profile group Taxonomic units queriedConcept notes and query rules IV2Great groups: All “pale” great groups of Aridisols, Mollisols and Alfisols, and Albaqualfs and Albaquults that also have abrupt clay increase with depth Strongly developed soils formed in old alluvial deposits. Query rules: Cannot be on hillslopes or mountains.

57 Tabel 1. Faktor A, penyebutan kelompok profil tanah melalui data taxonomi yg disimpan dalam NASIS Sumber: Rivised SISR: STORIE INDEX Soil Ratings Storie 1978 profile group Revised profile group Taxonomic units queriedConcept notes and query rules V3Suborder: Durids Great groups: Petro, Dur, Fragi, Petra, Plinth Subgroups: Duric Haplosalids, Petrogypsic Haplosalids Other: Calciudolls that have a petrocalcic horizon Soils with hardpans formed in old alluvial deposits. Query rules: Cannot be on hillslopes or mountains. Fuzzy rule depth to restrictive horizon used to generate score.

58 Table 1. Faktor A, penyebutan kelompok profil tanah melalui data taxonomi yg disimpan dalam NASIS Sumber: Rivised SISR: STORIE INDEX Soil Ratings Storie 1978 profile group Revised profile group Taxonomic units queriedConcept notes and query rules VI2Not includedGroup VI was dropped because of its similarity to Group IV. VII-IX4All colluvial and residual soils formed on mountains and hillslopes Groups VII to IX were combined based on soil depth in Storie 1978 to bedrock or consolidated material. Soils on upland areas. Fuzzy rule depth to lithic or paralithic contact used to generate score.

59 Table 1. Faktor A, penyebutan kelompok profil tanah melalui data taxonomi yg disimpan dalam NASIS Sumber: Rivised SISR: STORIE INDEX Soil Ratings Storie 1978 profile group Revised profile group Taxonomic units queriedConcept notes and query rules I1

60 Figure 2. Fuzzy logic rating functions “more is better” to define the effective soil depth in Factor A, soil profile group. A: A rating curve for Profile Groups I–III. B: A rating curve for Profile Group IV describing the depth to an abrupt texture change. C: A rating curve for Profile Group V depth to a cemented pan. D: A rating curve for Profile Groups VII–IX describing the depth to bedrock Sumber: Rivised SISR: STORIE INDEX Soil Ratings

61 Tabel 2. Skore penilaian “Crisp” untuk Faktor B, Kelas tekstur horison permukaan Sumber: Rivised SISR: STORIE INDEX Soil Ratings Kelas Tekstur Lap. Permukaan Nilai very fine sandy loam, fine sandy loam, loam, silt, silt loam100 loamy very fine sand, sandy loam, sandy clay loam, calcareous silty clay loam, clay loam 95 coarse sandy loam, loamy fine sand, noncalcareous silty clay loam, clay loam90 loamy sand, very fine sand80 fine sand, loamy coarse sand, sandy clay 65 Pasir, Liat Berdebu60 Liat = Clay50 Pasir Kasar30

62 Figure 3. “Less is better” fuzzy rating curve for Factor B, surface rock fragment content. Straight line segments represent three classes of rock fragment volume percent populated in NASIS: 0- 15, and > 35. Sumber: Rivised SISR: STORIE INDEX Soil Ratings

63 Figure 4. “Less is better” fuzzy rating curve for Factor C, slope. Most soil scientists express slope gradient as a percent, the difference in elevation between two points as a percentage of the distance between those points. Slope 100% setara dengan sudut kemiringan 45°. Sumber: Rivised SISR: STORIE INDEX Soil Ratings

64 Figure 5A. “Optimal” fuzzy rating curve for Factor X, pH, in the surface layer. Nilai pH optimal antara pH 5.5 dan 8.5. Kondisi ekstrim terjadi pada nilai pH rendah. Sumber: Rivised SISR: STORIE INDEX Soil Ratings

65 Figure 5b. “Optimal: less is better” fuzzy rating curve for Factor X, surface soil sodium adsorption ratio. Skore menjadi lebih rendah kalau nilai SAR lebih dari 7. Sumber: Rivised SISR: STORIE INDEX Soil Ratings

66 Figure 5C. “Optimal: less is better” fuzzy rating curve for Factor X, surface soil electrical conductivity (EC). Skor menjadi lebih rendah kalau nilai EC melebihi 1.0 Rivised SISR: STORIE INDEX Soil Ratings Sumber:

67 I.Tanah-tanah pda kipas-aluvial muda, dataran banjir, atau deposir sekunder lainnya yg belum berkembang Profiles …………………….100 % X - shallow phases (on consolidated material). 2 feet deep …… % X - shallow phases (on consolidated material). 3 feet deep …… 70 % G - extremely gravelly subsoils …… % S - stratified clay subsoils …… % Sumber: FAKTOR A. Penilaian Karakter Fisik Profil II. Tanah-tanah pada Kipas-aluvial muda, dataran banjir. or other secondary deposits having slightly developed profiles …… % X - shallow phases (on consolidated material). 2 feet deep … X - shallow phases (on consolidated material). 3 feet deep ….. 70 G - extremely gravelly subsoils … S - stratified clay subsoils …

68 III. Tanah-tanah pd kipas aluvial tua, dataran aluvial atau terras tua, perkembangan profilnya moderat (subsoil agak rapat) … % X - shallow phases (on consolidated material). 2 feet deep … X - shallow phases (on consolidated material). 3 feet deep … G - extremely gravelly subsoils … SISR: STORIE INDEX Soil Ratings IV. Tanah-tanah pd dataran atau terras tua, profilnya sudah berkembang (subsoil liat padat) … % V. Tanah-tanah pada Dataran atau Terras tua yg mempunyai subsoil cadas-keras: 1.pada kedalaman kurang 1 foot …… at 1 to 2 feet … at 2 to 3 feet … at 3 to 4 feet … At 4 to 6 feet …

69 VI. Tanah-tanah pada terras tua dan lahan kering dengan subsoil liat padat, bahan induknya material padu atau agak padu …… VII. Tanah-tanah di lahan kering yang lapisan bawahnya keras pada kedalaman: 1.at less than 1 foot … at 1 to 2 feet … at 2 to 3 feet … at 3 to 4 feet … At 4 to 6 feet … at more than 6 feet …… 100 Sumber: SISR: STORIE INDEX Soil Ratings

70 VIII. Tanah-tanah di lahan kering yang lapisan bawahnya batuan sedimen 1.at less than 1 foot … at 1 to 2 feet … at 2 to 3 feet … at 3 to 4 feet … at 4 to 6 feet … at more than 6 feet … IX. Tanah-tanah di lahan kering yg lapisan bawahnya material lunak 1.at less than 1 foot … at 1 to 2 feet … at 2 to 3 feet … at 3 to 4 feet … at 4 to 6 feet … at more than 6 feet … SISR: STORIE INDEX Soil Ratings

71 FAKTOR B --- Penilaian atas dasar tekstur lapisan permukaan Tekstur Medium : 1.fine sandy loam … loam … silt loam … Sandy loam …… 95 5.silty clay loam, calcareous … Silty clay loam. noncalcareous … clay loam. calcareous … clay loam. noncalcareous … Tekstur Berat atau Halus: 1.silty clay. highly calcareous … silty clay. noncalcareous … clay. Highly calcareous …… clay. noncalcareous … Sumber: SISR: STORIE INDEX Soil Ratings

72 Tekstur Ringan atau Kasar: coarse sandy loam 90 Loamy sand 80 very fine sand 80 Fine sand 65 sand 60 Coarse sand Sumber: SISR: STORIE INDEX Soil Ratings Berkerikil : Lempung-berpasir-halus Berkerikil Lempung Berkerikil gravelly silt loam gravelly sandy loam gravelly clay loam gravelly clay Pasir Berkerikil 20-30

73 Sumber: SISR: STORIE INDEX Soil Ratings Penilaian Kondisi Berbatu: Lempung-berpasir-halur Berbatu Lempung Berbatu stony silt loam60-80 stony sandy loam50-70 stony clay loam60-80 stony clay40-70 Pasir berbatu10-40

74 Sumber: SISR: STORIE INDEX Soil Ratings Penilaian Fdaktor C atas dasar Slope A - Nearly level (0 to 2%)100 AA - Gently undulating (0 to 2%) B-Gently sloping (3 to 8%) BB-Undulating (3 to 8%) C-Moderately sloping (9-15%)80-95 CC-Rolling (9 to 15%)80-95 D-Strongly sloping (16 to 30%)70-80 DD-Hilly (16 to 30%)70-80 E - Curam (Slope %)30-50 F – Sangat Curam (45% dan lebih)5-30

75 Sumber: SISR: STORIE INDEX Soil Ratings Penilaian Faktor X, selain faktor A, B dan C Drainage: well-drained100 fairly well drained 1/ 1/80-90 moderately waterlogged 2/ 2/40-80 badly waterlogged 3/ 3/10-40 subject to overflowvariable Alkali: 4/ 4/ alkali-free100 slightly affected60-95 moderately affected30-60 moderately to strongly affected strongly affected5-15 Ketersediaan Hara (Tingkat Kesuburan Tanah): high100 fair poor80-95 very poor60-80 Acidity: according to degree 5/ 5/ 80-95

76 Sumber: SISR: STORIE INDEX Soil Ratings Penilaian Erosi Tanah: Tidak ada erosi atau sedikit sekali100 detrimental deposition75-95 moderate sheet erosion80-95 occasional shallow gullies70-90 moderate sheet erosion with: shallow gullies60-80 deep gullies10-70 moderate sheet erosion with: deep gullies10-60 severe sheet erosion50-80 severe sheet erosion with: shallow gullies40-50 Jurang-erosi dalam10-40 Erosi sangat parah10-40 Erosi angin moderat80-95 Erosi angin parah30-80

77 Sumber: SISR: STORIE INDEX Soil Ratings Microrelief: Rata-halus: Smooth100 Channels60-95 hogwallows60-95 low hummocks80-95 high hummocks20-60 dunes10-40

78 PENENTUAN GRADE TANAH Ada enam GRADE Tanah yang dideskripsikan menurut kisaran nilai indeks sbb: 1.Grade 1 (excellent): Soils that rate between 80 and 100 percent and which are suitable for a wide range of crops, including alfalfa, orchard, truck, and field crops. 2.Grade 2 (good): Soils that rate between 60 and 79 percent and which are suitable for most crops Yields are generally good to excellent. 3.Grade 3 (fair ): Soils that rate between 40 to 59 percent and which are generally of fair quality, with less wide range of suitability than grades 1 and 2 Soils in this grade may give good results with certain specialized crops. 4.Grade 4 (poor) : Soils that rate between 20 to 39 percent and which have a narrow range in their agricultural possibilities For example, a few soils in this grade may be good for rice, but not good for many other uses. 5.Grade 5 (very poor): Soils that rate between 10 and 19 percent are of very limited use except for pasture, because of adverse conditions such as shallowness, roughness, and alkali content. 6.Grade 6 (nonagricultural): Soils that rate less than 10 percent include, for example, tidelands, riverwash, soils of high alkali content, and steep broken land. SISR: STORIE INDEX Soil Ratings

79 Current terminology: 1/ moderately well drained 2/ somewhat poorly drained 3/ poorly to very poorly drained 4/ salinity/sodicity 5/ pH less than 50 Sumber: SISR: STORIE INDEX Soil Ratings

80 Tanah-tanah dinilai berdasarkan Indeks Storie This index expresses numerically the relative degree of suitability, or value, of a soil for general intensive agriculture. The rating is based on soil characteristics only and is obtained by evaluating such factors as depth, texture of the surface soil, intensity of subsoil, drainage, salts and alkali, and relief. Other factors, such as availability of water for irrigation, climate, and distance from markets that might determine the desirability of growing certain plants in a given locality are not considered. Therefore in itself the index cannot be considered as an index of land value. The index rating is given in the "Guide to Mapping Units" section of the Eastern Fresno Soil Survey document. Sumber: SISR: STORIE INDEX Soil Ratings

81 Empat faktor yang biasanya digunakan dalam penilaian Indeks Storie. Keempat Faktor ini adalah (A) karakteristik profil tanah ― terutama permeabilitas dan kedalaman tanah; (B) tekstur tanah permukaan; (C) slope; dan (X) faktor atau pembatas lainnya, seperti ketersediaan hara, banjir, drainage, salts dan alkali, erosion, dan micro-relief. Each of these four general factors is evaluated on the basis of a “100 percent” rating. A rating of 100 percent expresses the most favorable, or ideal condition; and lower percentage ratings are given for conditions less favorable for crop production. Sumber: SISR: STORIE INDEX Soil Ratings

82 Penilaian Indeks Storie untuk suatu tanah diperoleh dengan mengalikan keempat faktor tersebut, A, B, C, dan X; sehingga setiap faktor ikut menentukan nilai akhir. For example, a soil may have an excellent profile justifying a rating of 100 percent for factor A; excellent texture of the surface soil justifying 100 percent for factor B; a smooth nearly level surface justifying 100 percent for factor C, but a high accumulation of salts of alkali that would give a rating of 10 percent for factor X. Multiplying these four ratings gives an index rating of 10 for this soil. The high accumulation of salts or alkali would dominate in determining the quality of the soil, render it unproductive for crops, and justify the low index rating of 10 consistent with a “most-limiting factor” Sumber: SISR: STORIE INDEX Soil Ratings

83 Indeks Storie (i) untuk menilai suatu tanah merupakan ekspresi numerik yg menyatakan derajat sampai dimana kondisi tanah aktual sesuai untuk pertumbuhan tanaman pada kondisi lingkungan (iklim) yang baik. Dalam menghitung Indeks Storie ini ada tiga faktor yang dipertimbangkan, yaitu: Faktor A, profil tanah; Faktor B, tekstur lapisan tanah permukaan; dan Faktor C, pemodifikasi kondisi tanah, seperti drainage, alkali, kemasaman, dll. Each of these three factors is evaluated on a percentage basis, the most favorable or ideal conditions being rated as 100 percent. The values of factors A, B, and C are then multiplied, the result being the index number. Sumber: SISR: STORIE INDEX Soil Ratings

84 The index method is a decided departure from the usual score card methods of judging and evaluating soils, in which the various soil characteristics are given values on the basis of 100 op 1000, and after rating each characteristic on this basis, the merits are added to ascertain the final rating of the soil. With many factors to be considered, no single factor can be given very heavy weight, and complete failure in one or more features may still leave the soil rating comparatively high. Sumber: SISR: STORIE INDEX Soil Ratings

85 The multiplication of factors, A, B, and C permits any one of these to completely dominate the index rating. For illustration, a soil may be a deep recent alluvial deposit of fine sandy loam, probably as ideal in profile and texture as one could find, and rating 100 percent for factors A and B. But if it was heavily charged with alkali, its C rating might be 10 or lower. Multiplying factors A, B, and C would give a final index value of 10, while under the score card method, where 'alkali‘ would hardly be given a value of more than 20 points, the rating would be 80 or more! Heavy accumulations of alkali would absolutely dominate the soil, rendering it valueless for any economic crop, and the index rating cf 10 or less would be justified. Sumber: SISR: STORIE INDEX Soil Ratings

86 For use in California, the soil profiles, factor A, have been divided into six groups, five being made up of secondary soils and one of primary soils. In some eastern states, for instance, Pennsylvania, this distribution might be reversed. The primary soils could there well be divided into four or five major groups, while the secondary soils could be combined into one or two, with subgroups where necessary. The soil series within each group are given ratings whose value depends upon the character of the series profile, particularly the characteristics of the subsoils or B horizons. Profiles with deep subsoils pervious to water and roots, yet sufficiently retentive to carry crops through moderate drought periods and which are free from any stratification or other conditions that would retard plant growth are rated as 100 percent. Profiles with dense claypan subsoils or with hardpan horizons are rated at 5 to 60 percent, depending on the density of the claypan, or the depth to the hardpan. Primary soils are rated at from 20 to 70, depending on the character of the subsoil and the depth to bedrock. Sumber: SISR: STORIE INDEX Soil Ratings

87 The B factor evaluates the character of the surface soils, which are divided into four textural groups—light, medium, medium-heavy, and heavy textured, with two additional groups to cover the textural grades that include gravel and stone. The B factor rates not only the soil texture, but also those other characteristics that are more or less dependent on texture, such as consistence, porosity, permeability and tilth. These factors determine the response of the soil to tillage operations, the rate of water absorption, the characteristics of the seedbeds and other features that are vital in agricultural work. Fine sandy loams, loams, and silt loams are considered ideal and are rated as 100, while heavy clays rate from 50 to 70. Stony sands may rate as low as 10 percent. The applications of this index method in other states and under other climatic conditions might require some rearrangement of the values assigned to factor B. Sumber: SISR: STORIE INDEX Soil Ratings

88 Factor C was found to be most difficult. It is intended to cover those modifying conditions that are fundamentally related to the soil, or are inherent in the soil itself. Among these are conditions of excessive alkalinity or acidity of the soil, marked infertility, conditions of poor drainage, shallow, steep, or eroded phases untypical of the soil type, and the like. Most of these conditions are usually reflected in the soil profile and are considered in the values assigned under factor A. But the degree of intensity of those conditions, or their irregular occurrence may not be expressed in the A or B factors, hence the introduction of this C factor to cover such conditions whenever they exist in sufficient degree as to modify the soil-plant relationships. Factors A and B essentially evaluate the Soil Type, factor A covering the series characteristics and particularly those of the subsoils or B horizons, while factor B covers the surface soils or the A horizons. In most locations the third modifying factor C does not appear in the evaluation. Sumber: SISR: STORIE INDEX Soil Ratings

89 Metode Indeks Storie bertumpu pada informasi yang dikumpulkan dalam survei tanah, dan sangat mudah dilakukan kalau survei tanah telah diselesaikan. Kalau tidak ada survei tanah maka harus dilakukan pengambilan contoh tanah lapisan atas (topsoil) dan tanah lapisan bawah (subsoil). Obviously, it is not possible to properly evaluate, assess or appraise the soil without knowing the facts regarding the soil characteristics, either through the use of the soil maps, or by actual soil exploration. Guesses as to soil conditions, based on a look at growing crops or native cover, are usually very unreliable and often misleading. For Federal Land Bank loans, which may run 20 to 35 years, the soil factor must be properly evaluated in making the land appraisals. Sumber: SISR: STORIE INDEX Soil Ratings

90 The Storie Index method is being used in California by the assessors in several counties and by appraisers for the Federal Land Bank and other financial institutions. In the Imperial Valley, where the climate, water supply, transportation, markets, and conditions other than those inherent in the soil are all quite uniform, the index rating becomes essentially a land evaluation. In Riverside County, where the availability and quality of irrigation water determines whether or not the land can be used at all and where such influences as micro-climate (with variations of only a few degrees in minimum winter temperatures) may determine whether or not citrus fruits can be produced on a given site, the soil factor becomes only one of many factors that must be considered in arriving at the land evaluation. Sumber: SISR: STORIE INDEX Soil Ratings

91 The soils in the area, primarily used for cropland, in the Sacramento Valley, and rangeland, in the Coast Range foothills, are rated in Table 10a according to the Storie index (Storie, 1933; 1976). The soils in the higher Coast Range, primarily used for timberland, are in Table 10b according to the Storie index (Storie, 1948). These indexes express numerically the relative degree of suitability of a soil for general intensive agricultural uses or timber uses at the time of the evaluation. Sumber: STORIE INDEX

92 Index for cropland and rangeland The rating is based on soil characteristics and is obtained by evaluating soil surface and subsurface chemical and physical properties, as well as landscape surface features. The original "Soil-Rating Chart" (Storie 1976). Some of the terminology used in this chart is not used today. However, when the ratings were developed, they were compared to today’s terminology to create the most logical estimate for the rating. Not considered in the rating are availability of water for irrigation, local climate, size and accessibility of mapped areas, distance to markets and other factors that might determine the desirability of growing certain plants in a given locality. Therefore, the index should not be used as the only indicator of land value. Where the local economic and geographic factors are known to the user, however, the Storie index may provide additional objective information for land tract value comparisons. Sumber: STORIE INDEX

93 INDEKS UNTUK LAHAN PERTANIAN & GEMBALAAN Empat faktor yg digunakan untuk menentukan nilai Indeks: 1.Permeabilitas tanah, available water capacity, and depth of the soil 2.Tekstur tanah lapisan permukaan 3.Slope dominan dari tubuh tanah 4.Kondisi lainnya Other conditions more readily subject to management or modification by the land user. In this area these conditions include drainage and flooding, salinity and alkalinity, fertility, acidity, erosion, and microrelief. For some soils, more than one of these X conditions are used in determining the rating. Sumber: STORIE INDEX

94 INDEKS UNTUK LAHAN PERTANIAN A rating of 100 percent expresses the most favorable, or ideal, condition for general crop production. Lower percentage ratings are assigned for less favorable conditions or characteristics. Factor ratings, in percentages, are selected from tables prepared from data and yields. Certain properties are assigned a range of values to allow for variations in the properties to plant growth and crop yields. Certain properties are assigned a range of values to allow for variations in the properties that affect the suitability of the soil for general agricultural purposes. The index rating for a soil component of a map unit is obtained by multiplying the percentage rating values given to its four factors, A, B, C, and X. If more than one condition is recognized for the X factor for a soil, the value for each condition acts as a multiplier. Therefore any of the general factors or X factors conditions may dominate or control the final rating. Sumber: STORIE INDEX

95 Indeks Untuk Lahan Tanaman dan Lahan Gembalaan If a map unit consists primarily of one named soil series (a consociation), the index rating for the named soil component equals the index rating for the map unit. If a map unit consists of more than one named component (a complex), ratings are assigned to each named component (soil series or miscellaneous area, such as "Rock outcrop"). Inclusions of other soils or minor components not named in the map unit name, are not used in the calculations. Map units are assigned grades according to their suitability for general intensive agriculture as shown by their Storie index ratings. The six grades and their range in index ratings are: Grade 1—80 to 100 Grade 2—60 to 79 Grade 3—40 to 59 Grade 4—20 to 39 Grade 5—10 to 19 Grade 6—less than 10 Sumber: STORIE INDEX

96 INDEKS UNTUK LAHAN PERTANIAN 1.Grade 1 are well suited to intensively cultivated crops that are climatically adapted to the region. 2.Grade 2 soils are good agricultural soils, although they are not so desirable as soils in grade 1 because of a less permeable subsoil, deep cemented layers (e.g., duripans), a gravelly or moderately fine textured surface layer, moderate or strong slopes, restricted drainage, low available water capacity, lower soil fertility, or a slight or moderate hazard of flooding. 3.Grade 3 soils are only fairly well suited to agriculture because of moderate soil depth; moderate to steep slopes, restricted permeability in the subsoil; a clayey, sandy, or gravelly surface layer; somewhat restricted drainage; acidity; low fertility; or a hazard of flooding. 4.Grade 4 soils are poorly suited to agriculture. They are more limited in their agricultural potential than the soils in grade 3 because of restrictions, such as a shallower depth; steeper slopes; poorer drainage; a less permeable subsoil; a gravelly, sandy, or clayey surface layer; channeled or hummocky microrelief; acidity. 5.Grade 5 soils are very poorly suited to agriculture and are seldom cultivated. They are more commonly used as pasture, rangeland, or woodland. 6.Grade 6 soils and miscellaneous areas are not suited to agriculture because of very severe or extreme limitations. They are better suited to limited use as rangeland, protective habitat, woodland, or watershed. Sumber: STORIE INDEX

97 INDEKS UNTUK LAHAN HUTAN The rating is based on soil characteristics and is obtained by evaluating soil surface and subsurface chemical and physical properties, as well as climatic features. The original "Timber Soil Rating Chart" (Storie 1948). Some of the terminology used in this chart is not used today. However, when the ratings were developed, they were compared to today’s terminology to create the most logical estimate for the rating. Not considered in the rating are size and accessibility of mapped areas, distance to markets and other factors that might determine the desirability of timber production in a given locality. Therefore, the index should not be used as the only indicator of timber production. Where the local economic and geographic factors are known to the user, however, the Storie index may provide additional objective information for timber production. Lima faktor yg digunakan untuk menentukan nilai indeks : 1.Kedalaman Tanah dan Tekstur tanah 2.Permeabilitas Tanah 3.Karakteristik Kimia Tanah. 4.Drainage dan runoff. 5.Iklim. Sumber: STORIE INDEX

98 INDEKS UNTUK LAHAN HUTAN The index rating for a soil component of a map unit is obtained by multiplying the percentage rating values given to its four factors, A, B, C, D, and E. If a map unit consists primarily of one named soil series (a consociation), the index rating for the named soil component equals the index rating for the map unit. If a map unit consists of more than one named component (a complex), ratings are assigned to each named component, except rock out crop. Miscellaneous areas are considered to be unsuited for timber production, and are not rated or considered zero. Inclusions of other soils or minor components not named in the map unit name, are not used in the calculations. Timber site ratings in percent were assigned adjective ratings according to their suitability for general intensive timber production as shown by figure 1 "Relationship Between Timber Site Rating and Height - Age Index" in the appendices showing the "Timber Soil Rating". The five ratings and their range in index ratings are: Redwood—100 to 120 High—85 to 99 Medium—50 to 84 Low—30 to 49 Non- Timber—0 to 29 Sumber: STORIE INDEX

99 KELAS KAPABILITAS TANAH STORIE INDEX

100 UNIT KAPABILITAS TANAH Unit Ka- pabilitas Sifat Tanah atau Faktor Pembatas 1Ada bahaya aktual atau potensiao erosi tanah oleh air atau angin. 2 Bahaya Drainage atau genangan (swp or poorly drained, flooded or ponded) 3Subsoil mempunyai permeabilitas lambat atau sangat lambat. 4Tekstur kasar atau berkerikil. 5Tekstur halus atau snagat halus. 6Salinity or alkali, sufficient to constitute a continuing limitation or hazard. 7Stones, cobbles, or rocks sufficient to interfere with tillage. 8Hardpan or hard unweathered bedrock within the root zone. 9Low inherent fertility, associated with strong acidity, low calcium- 10High organic matter content - peats and mucks. 11 Coarse sandy or very gravelly substrata limiting to root penetration and moisture retention

101 Studi lapangan dimulai tahun 1947 untuk menganalisis hubungan antara tanah, iklim dan kualitas lokasi hutan tanaman (timber). Empat faktor tanah disimpulkan mempengaruhi atau membatasi pertumbuhan jenis conifers di California. Keempat faktor ini adalah A – Kedalaman tanah dan tekstur tanah; B – Permeabilitas tanah; C – Karakteristik kimia tanah; D - Drainage dan runoff. Selain itu juga ada faktor iklim. High sites for growing conifers in California need a deep soil of sufficiently fine textured to hold about 12% of more of moisture; a permeable profile; have no toxic chemical characteristics; be of acid reaction; well drained; and have a total annual rainfall of more than 40 inches. Hasil penilaian pendahuluan berdasarkan penetapan nilai persentase untuk lima faktor : A – Kedalaman tanah dan tekstur; B – permeabilitas tanah; C – sifat kimia tanah; D - Drainage dan runoff; E - Iklim. Four climatic zones are considered in rating the timber sites in the Sierra Nevada and Coast Range Mountains of California and Nevada. Timber Site Rating = A x B x C x D x E. Sumber: TIMBER SOIL RATINGS

102 Timber Soil Rating Chart Indeks untuk menilai kesesuaian tanah untuk Hutan Tanaman Kayu di California Faktor A: Depth-Texture (tidak ada efek penilaian untuk tekstur dengan kapasitas air tersedia 12% atau lebih.) Sumber: TIMBER SOIL RATINGS Kedalaman-TeksturNilai (%) Kelas Kedalaman Kedalaman lebih 72”

103 Faktor B: Permeabilitas Tanah Sumber: TIMBER SOIL RATINGS Permeabilitas Nilai (%) Kelompok Profil Tanah Moderately rapid & rapidly permeable profiles 100 I; II; VII-I, II; VIII-I, II; IX-I, II Moderately slow & slowly permeable profiles III; III+; VII-III, III+; VIII-III, III+; IX-III, III Very slowly permeable profile IV; V; VII-IV; VIII-IV; IX-IV

104 Faktor C: Kimia Tanah (Alkalinity, Salinity, dll.) Sumber: TIMBER SOIL RATINGS Efek Kimiawi Nilai (%) Kelas Toksisitas Tidak ada 100 Ringan 80-90S Moderat 20-80M Parah / Berat / Kuat 0-20A

105 Faktor D: Drainage-Runoff Sumber: TIMBER SOIL RATINGS DrainageNilai (%) Drainage symbol Well & moderately well 100 w Excessively r Somewhat poorly i Buruk dan Sangat Buruk (Sgt Jelek) p

106 Faktor E: Iklim Sumber: TIMBER SOIL RATINGS CF--Coastal Fog (Redwood) CR--Coastal Range (Douglas fir) WS--Westside Sierra (Pine) ES--Eastside Sierra Pine (P.J.) Rainfall (in.) Rating percent Rainfall (in.) Rating percent Rainfall (in.) Rating percent Rainfall (in.) Rating percent

107 Pentingnya Klasifikasi Tanah dan Penilaian Tanah bagi Lokasi Hutan Timber Klasifikasi tanah bersama dengan nilai tanah untuk kualitas lokasi hutan tanaman (timber) akan memperkuat survei sumberdaya hutan di California melalui dua cara: First it will facilitate and improve the quality of the timber site classification. Previously this classification has been base entirely on the height-age relationship of dominant trees without reference to the soil. Ratings were satisfactorily made where dominants were present, as in the case of virgin timber or older second growth. On the other hand difficulties were encountered in making reliable ratings in many cut-over or burned-over areas where suitable dominants were infrequent or entirely absent. Sumber: TIMBER SOIL RATINGS

108 Pentingnya Klasifikasi Tanah dan Penilaian Tanah bagi Lokasi Hutan Timber Di beberapa lokasi, dimana tidak ada pertumbuhan tegakan kayu timber, maka tidak dapat ditentukan apakah lokasi itu sesuai untuk hutan tanaman kayu timber. Kesulitan ini dicoba diatasi dengan jalan menilai lokasi tersebut berdasarkan kualitas tanahnya. Second, the maps produced by the survey, since they show the location of good, fair, poor, and unsuitable sites for growing various kinds of timber trees, will have greater usefulness to those interested in managing forest lands for timber crops. Sumber: TIMBER SOIL RATINGS

109 Hubungan antara Rating Tapak Hutan dengan Indeks tinggi-umur Sumber : TIMBER SOIL RATINGS

110 STORIE INDEX OF SOILS Sumber: STELA – April 2013


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