EVALUASI LAHAN DAN INDIKATOR LAHAN

1. EVALUASI LAHAN DAN INDIKATOR LAHAN BAHAN KAJIAN: STELA-SMNO.FPUB.APRIL2013

2. CONCEPTS, DEFINITIONS AND PRINCIPLES "Lahanadalah area tertentudipermukaanbumi, yang melingkupisemuaatributbiosfirdiatasdandibawahpermukaan, termasukiklimdidekatpermukaan, tanahdanbentuklahan, hidrologipermukaan (termasukdanaudangkal, sungai, rawa-rawa), the near-surface sedimentary layers and associated groundwater reserve, populasitumbuhandanbinatang, polapermukimandansifatfisikakibataktivitasmanusia (terras, bangunan air dan drainage, jalanrayadanbangunangedung, dll.).“ Sumber: FAO Land and Water Bulletin No. 5. 1997

3. Fungsi-fungsilahan: FungsiProduksi FungsiLingkunganBiotik Fungsiregulasiiklim · hydrologic function · storage function · waste and pollution control function · living space function · archive or heritage function · connective space function Sumber: FAO Land and Water Bulletin No. 5. 1997

4. FUNGSI PRODUKSI Lahanmerupakan basis bagiberbagaisistempenunjangkehidupan, melaluiproduksibiomasa yang menyediakanmakanan, pakan-ternak, serat, bahan-bakar, bahanbangunandan material biotiklainnyabagimanusia, secaralangsungataumelaluibudidayaternak, termasukakuakulturdanperikanantangkap. Sumber: FAO Land and Water Bulletin No. 5. 1997

5. FUNGSI LINGKUNGAN BIOTIK Lahanmerupakan basis bagibuiodiversitasterrestrisdenganmenyediakan habitat biologisdan plasma nutfahbagitanaman, binatang, danmikroba yang hidupdiatasdandibawahpermukaan. Sumber: FAO Land and Water Bulletin No. 5. 1997

6. FUNGSI LAHAN: REGULASI IKLIM land and its use are a source and sink of greenhouse gases and form a co-determinant of the global energy balance - reflection, absorption and transformation of radiative energy of the sun, and of the global hydrological cycle FungsiLahan: KoneksiRuang land provides space for the transport of people, inputs and produce, and for the movement of plants and animals between discrete areas of natural ecosystems Sumber: FAO Land and Water Bulletin No. 5. 1997

7. FUNGSI LAHAN FUNGSI HIDROLOGI Land regulates the storage and flow of surface and groundwater resources, and influences their quality FUNGSI PENGENDALI PENCEMARAN DAN LIMBAH land has a receptive, filtering, buffering and transforming function of hazardous compounds FUNGSI GUDANG land is a storehouse of raw materials and minerals for human use Sumber: FAO Land and Water Bulletin No. 5. 1997

8. FUNGSI RUANG KEHIDUPAN land provides the physical basis for human settlements, industrial plants and social activities such as sports and recreation. FUNGSI ARSIP ATAU WARISAN Land is a medium to store and protect the evidence of the cultural history of humankind, and source of information on past climatic conditions and past land uses. Sumber: FAO Land and Water Bulletin No. 5. 1997

9. LahanmempunyaiAtribut, Karakteristik, Sifat & Ciri, danKualuitas (atauKondisi/Pembatas): an attribute, or variable, is a neutral, over-arching term for a single or compound aspect of the land; a characteristic is an attribute which is easily noticed and which serves as a distinguishing element for different types of land; it may or may not have a practical meaning (e.g., soil colour or texture, or height of forest cover are characteristics without giving direct information on land quality); a property is an attribute that already gives a degree of information on the value of the land type; a land quality (or limitation) is a complex attribute of land which acts in a manner distinct from the actions of other land qualities in its influence on the suitability of land for a specified kind of use. Sumber: FAO Land and Water Bulletin No. 5. 1997

10. Land qualities are not absolute values, but have to be assessed in relation to the functions of the land and the specific land use that one has in mind. Some examples: Land recently cleared from forest has a positive quality in respect of arable cropping (clearing, as "development costs", adding to the value of potential agricultural land), but has a negative quality in respect of sustainable use of the natural vegetative cover; Land with a high degree of short-distance variation in soil and terrain conditions has a positive quality for biodiversity, is a large drawback to large-scale mechanized arable farming, but has a smaller limitation - or even an advantage - for smallholders' mixed farming; The presence of scattered clumps of trees or shrubs in an open savannah area with harsh climatic conditions is a positive quality for extensive grazing (shelter against cold, heat or wind) but may be less important, or negative, for arable farming; The presence of small land parcels, of woody or stony hedgerows and terraces, or of archaeological remains, is a positive quality in relation to the archival function of the land, but can conflict with its production function; The propensity of the soil surface to seal and crust is a negative quality for arable farming (poor seedbed condition; reduced moisture intake of the soil), but is an asset of the land as regards water harvesting possibilities for crop growing in lower parts of the landscape wherever rainfall is submarginal. Sumber: FAO Land and Water Bulletin No. 5. 1997

11. KUALITAS LAHAN & PRODUKTIVITAS TANAMAN Crop yields (a resultant of many qualities listed below). KETERSEDIAAN LENGAS TANAH. KETERSEDIAAN HARA. KETERSEDIAAN OKSIGEN DI ZONE AKAR. Adequacy of foothold for roots. KONDISI PERKECAMBAHAN. Workability of the land (ease of cultivation). SALINITAS ATAU SODISITAS. TOKSISITAS TANAH. RESISTENSI TERHADAP EROSI TANAH. Pests and diseases related to the land. Flooding hazard (including frequency, periods of inundation). REGIM SUHU. RADIASI ENERGI DAN FOTOPERIODE. Climatic hazards affecting plant growth (including wind, hail, frost). Air humidity as affecting plant growth. PERIODE KERING UNTUK PEMASAKAN/PEMATANGAN TANAMAN. Sumber: FAO Land and Water Bulletin No. 5. 1997

12. Crop yields (a resultant of many qualities listed below). Crop production provides the food for human beings, fodder for animals and fiber for cloths. Land is the natural resource which is unchanged & the burden of the population is tremendously increasing, thereby decrease the area per capita. Therefore it is necessary to increase the production per unit area on available land. This necessitates the close study of all the factors of crop production viz. TANAH sebagai TEMPAT MENANAM TANAMAN Air yang dibutuhkandandigunakanolehtanaman Tanamanygmenghasilkanbahan-bahanpangandanpakan Ketrampilanpengelolaan (budidaya) olehpetani Iklimdiluarkendalimanusia, tetapimempengaruhipertumbuhandanproduksitanaman. Karaktergenetiktanamanygmenjadikekayaangenetikdandapatdieksploitasiuntukproduksitanaman. Sumber: http://agriinfo.in/?page=topic&superid=1&topicid=311

13. KETERSEDIAAN LENGAS TANAH Kapasitas air-tersediamerupakanjumlah air ygdapatdisimpantanahuntukdimanfaatkanolehtanaman. Air tanahiniditahandiantarakapasitas-lapangdantitik-layu. Kapasitaslapangmerupakan air ygditahandalamtanahygberdrainagebebasselamaduaharisetelahhujanatauirigasi. Titiklayumerupakankandungan air-tanahpadasaatmanakecambahbunga-mataharimengalamilayusecara irreversible. Available water is expressed as a volume fraction (0.20), as a percentage (20%), or as an amount (in inches). An example of a volume fraction is water in inches per inch of soil. If a soil has an available water fraction of 0.20, a 10 inch zone then contains 2 inches of available water. Sumber: http://soils.usda.gov/sqi/publications/files/avwater.pdf

14. KETERSEDIAAN LENGAS TANAH Tekstur Tanah Fraksi air tersedia Sands, and loamy sands and Less than 0.10 sandy loams in which the sand is not dominated by very fine sand Loamy sands and sandy loams 0.10 - 0.15 in which very fine sand is the dominant sand fraction, and loams, clay loam, sandy clay loam, and sandy clay Silty clay, and clay 0.10 - 0.20 Silt, silt loam, and silty clay loam 0.15 - 0.25 Sumber: http://soils.usda.gov/sqi/publications/files/avwater.pdf

15. KETERSEDIAAN HARA. This soil quality is decisive for successful low level input farming and to some extent also for intermediate input levels. Diagnostics related to nutrient availability are manifold. Important soil characteristics of the topsoil (0-30 cm) are: Texture/Structure, Organic Carbon (OC), pH and Total Exchangeable Bases (TEB). Untuk subsoil (30-100 cm), karakteristik yang sangatpenting : Tekstur/Structur, pH danTEB. BerbagaiKarakteristiktanahygrelevandenganketersediaanharadalamtanahbternyatasalingberkorelasi. Sehinggafaktorpembatasinidikombinasikandengankarakteristiktanahygmencerminkankualitastanah. Sumber: http://www.fao.org/nr/land/soils/harmonized-world-soil-database/soil-quality-for-crop-production/en/

16. pH – KEMASAMAN TANAH Crops vary in their response to pH; calcifuge plants dislike lime while calciphilous plants are lime-loving. There are very few crops that grow well in calcareous soils that do not grow equally well at a pH above 6 under lime-free conditions. Several crops, such as tea, require acid conditions. Many crops are affected by micro-nutrient deficiencies or toxicities at certain pH levels. Ketersediaanharamikrodanmakrodipengaruhiolehkondisi pH tanah; akantetapiketersediaanharainijugaberagam dui antarajenis-jenistanaman. Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.10%20sodicity

17. Relative availability of common elements in mineral soils with pH (after Truog 1948) Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.10%20sodicity

18. KAPASITAS RETENSI HARA Nutrient retention capacity is of particular importance for the effectiveness of fertilizer applications and is therefore of special relevance for intermediate and high input level cropping conditions.Nutrient retention capacity refers to the capacity of the soil to retain added nutrients against losses caused by leaching. Plant nutrients are held in the soil on the exchange sites provided by the clay fraction, organic matter and the clay-humus complex. Losses vary with the intensity of leaching which is determined by the rate of drainage of soil moisture through the soil profile. Soil texture affects nutrient retention capacity in two ways, through its effects on available exchange sites on the clay minerals and by soil permeability.The soil characteristics used for topsoil are respectively: Organic Carbon (OC), Soil Texture (Text), Base Saturation (BS), Cation Exchange Capacity of soil (CECsoil), pH, and Cation Exchange Capacity of clay fraction (CECclay). Soil pH serves as indicator for aluminum toxicity and for micro-nutrient deficiencies. Sumber: http://www.fao.org/nr/land/soils/harmonized-world-soil-database/soil-quality-for-crop-production/en/

19. KetersediaanOksigendi Zone Perakaran Oxygen availability in soils is largely defined by drainage characteristics of soils. The determination of soil drainage classes is based on procedures developed at FAO (FAO 1995). These procedures take into account soil type, soil texture, soil phases and terrain slope. Apart from drainage characteristics, the soil quality of oxygen availability may be influenced by soil and terrain characteristics that are defined through the occurrence of specific soil phases. Sumber: http://www.fao.org/nr/land/soils/harmonized-world-soil-database/soil-quality-for-crop-production/en/

20. TEMPAT PANCANGNYA AKAR TANAMAN The rooting depth affects the total available water capacity in the soil. A soil that has a root barrier at 20 inches and an available water fraction of 0.20 has 4 inches of available water capacity. Another soil, that has a lower available water fraction of 0.10, would, if the roots extended to a depth of 60 inches, have 6 inches of available water capacity. For shallow rooting crops, like onions, the available water below 1-2 feet has little significance. For deeper rooting crops, like corn, the available water at the greater depth is very important. Sumber:http://soils.usda.gov/sqi/publications/files/avwater.pdf

21. KONDISI UNTUK PERKECAMBAHAN KONDISI PERAKARAN Rooting conditions include effective soil depth (cm) and effective soil volume (vol. %) related to presence of gravel and stoniness. Rooting conditions may be affected by the presence of a soil phase either limiting the effective rooting depth or decreasing the effective volume accessible for root penetration. Rooting conditions address various relations between soil conditions of the rooting zone and crop growth. The following factors are considered in the evaluation: Adequacy of foothold, i.e., sufficient soil depth for the crop for anchoring; available soil volume and penetrability of the soil for roots to extract nutrients; space for root and tuber crops for expansion and economic yield in the soil; and absence of shrinking and swelling properties (vertic) affecting root and tuber crops. Soil depth/volume limitations affect root penetration and may constrain yield formation (roots and tubers). Relevant soil properties considered are: soil depth, soil texture/structure, vertic properties, gelic properties, petric properties and presence of coarse fragments. This soil quality is estimated by multiplying of the soil depth limitation with the most limiting soil or soil phase property . Sumber: http://www.fao.org/nr/land/soils/harmonized-world-soil-database/soil-quality-for-crop-production/en/

22. KONDISI PERAKARAN. Soil phases that relevant for rooting conditions vary somewhat with source of soil map and soil classification used. In the HWSD these are: FAO 74 soil phases: stony, lithic, petric, petrocalcic, petrogypsic, petroferric, fragipan and duripan. FAO 90 soil phases: rudic, lithic, pertroferric, placic, skeletic, fragipan and duripan. ESB soil phases and other soil depth/volume related characteristics: stony, lithic, petrocalcic, petroferric, fragipan and duripan, and presence of gravel or concretions, obstacles to roots (6 classes), and impermeable layers (4 classes). Sumber: http://www.fao.org/nr/land/soils/harmonized-world-soil-database/soil-quality-for-crop-production/en/

23. Workability of the land (ease of cultivation). Workability or ease of tillage depends on interrelated soil characteristics such as texture, structure, organic matter content, soil consistence/bulk density, the occurrence of gravel or stones in the profile or at the soil surface, and the presence of continuous hard rock at shallow depth as well as rock outcrops. Some soils are easy to work independent of moisture conditions, other soils are only manageable at an adequate moisture status, in particular for manual cultivation or light machinery. Irregular soil depth, gravel and stones in the profile and rock outcrops, might prevent the use of heavy farm machinery. Sumber: http://www.fao.org/nr/land/soils/harmonized-world-soil-database/soil-quality-for-crop-production/en/

24. Salinity or sodicity. KELEBIHAN GARAM Akumulasigaram-garamdapatmenyebabkansalinitas. Excess of free salts referred to as soil salinity is measured as Electric Conductivity (EC in dS/m) or as saturation of the exchange complex with sodium ions, which is referred to as sodicity or sodium alkalinity and is measured as Exchangeable Sodium Percentage (ESP). Salinity affects crops through inhibiting the uptake of water. Moderate salinity affects growth and reduces yields; high salinity levels may kill the crop. Sodicity causes sodium toxicity and affects soil structure leading to massive or coarse columnar structure with low permeability. Apart from soil salinity and sodicity, conditions indicated by saline (salic) and sodic soil phases may affect crop growth and yields. Dalamkasuskejadiansimultantanah-tanah saline (salik) dansodik, makafaktorpembatasnyadigabungkan. Faktor yang paling membatasidiantarasalinitastanahdan/atausodisitastanah, dankejadiantanah saline (salic) dan/atausodik, makafaktoritulah yang ditetapkansebagaipembatas. Sumber: http://www.fao.org/nr/land/soils/harmonized-world-soil-database/soil-quality-for-crop-production/en/

25. Salinity The adverse effects of soil salinity on plant growth vary with the crop being grown. The presence of salinity in the soil solution resulting from either indigenous salt in the soil, or from salt added by irrigation water can affect growth (i) by reducing water available to the crop (the osmotic effect) and (ii) by increasing the concentration of certain ions that have a toxic effect on plant metabolism (the specific ion effect). Many plants, for example, barley, wheat and maize, are sensitive to the osmotic effect during germination and the early seedling stages, but have greater tolerances at later stages (USDA 1954). Salt damage is aggravated by hot, dry conditions and may be less severe in cool humid conditions. Data toleransigaramuntuktanamantertentutidakdapatdianggapsebagainilai yang “tetap”, tetapiharusdianggapsebagaisuatu “Arahan”. Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.10%20sodicity

26. Toleransigaramberbagaijenistanamanterhadapsalinitas, diukurdalamekstraksjenuhECe. Tanamanpangan. Sumber: Maas and Hoffmann 1977; James et al 1982.

27. EFEK FISIKA SODISITAS The presence of excessive amounts of exchangeable sodium in soil promotes the dispersion and swelling of clay minerals. The soil becomes impermeable to both air and water. The infiltration and hydraulic conductivity decrease to the extent that little or no water movement occurs. The soil is plastic when wet and becomes hard (brick-like) when dry. Tillage becomes difficult and soil crusting occurs. Recent research (Frenkelet al. 1978) has indicated that dispersion blocks soil pores, whereas swelling reduces pore sizes. Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.10%20sodicity

28. EFEK FISIKA SODISITAS The effect is most pronounced on soils containing clays which swell and shrink. Soils containing non-expanding clays such as kaolinite and sesquioxides are relatively insensitive to the physical effects of exchangeable sodium. However, heavy cracking clays may be so impermeable when wet that the decreased permeability associated with a high sodium content may not matter. Sodisitasditentukansebagai “the exchangeable sodium percentage” (ESP). Dalammenilaisodisitasharusdipertimbangkanperubahan ESP yang berlangsungsetelahlahandi-irigasi. Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.10%20sodicity

29. CRITICAL LIMITS FOR SODICITY TOLERANCE 1/ Ratings may be raised one level if permeability is more than 2 cm/hr (e.g. as in loamy and sandy soils). 2/ Soil depth ranges in cm. 3/ SAR may be used if ESP figures seem unreliable. Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.10%20sodicity

30. Sodium toxicity Plants vary considerably in their ability to tolerate sodium ions. Most tree crops and other woody-type perennials are particularly sensitive to low concentrations of sodium. Most annual crops are less sensitive, but may be affected by higher concentrations. Sodium toxicity is often modified and reduced if calcium is also present, therefore a reasonable evaluation of the potential toxicity is possible using the SAR for the soil water extract and the SAR of the irrigation water. Symptoms of sodium toxicity may appear only after a period of time during which toxic concentrations accumulate in the plant: the symptoms appear as a burn or drying of tissues first appearing at the outer edges of leaves. Table |40 can be used to evaluate the sodium hazard for representative crops. Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.10%20sodicity

31. TOLERANCE OF VARIOUS CROPS TO EXCHANGEABLE SODIUM (ESP) UNDER NONSALINE CONDITIONS Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.10%20sodicity

32. TOKSISITAS TANAH Low pH leads to acidity related toxicities, e.g., aluminum, iron, manganese toxicities, and to various deficiencies, e.g., of phosphorus and molybdenum. Calcareous soils exhibit generally micronutrient deficiencies, for instance of iron, manganese, and zinc and in some cases toxicity of molybdenum. Gypsum strongly limits available soil moisture. Tolerance of crops to calcium carbonate and gypsum varies widely (FAO, 1990; Sys, 1993). Low pH and high calcium carbonate and gypsum are mutually exclusive. Acidity related toxicities such as aluminum toxicities and micro-nutrient deficiencies are accounted for respectively in nutrient availability, and in nutrient retention capacity. This soil quality is therefore only including calcium carbonate and gypsum related toxicities. The most limiting of the combination of excess calcium carbonate and gypsum in the soil, and occurrence of petrocalcic and petrogypsic soil phases is selected for the quantification. Sumber: http://www.fao.org/nr/land/soils/harmonized-world-soil-database/soil-quality-for-crop-production/en/

33. KETAHANAN EROSI Climate, soil and topographic characteristics determine runoff and erosion potential from agricultural lands. The main factors causing soil erosion can be divided into three groups Energy factors: rainfall erosivity, runoff volume, wind strength, relief, slope angle, slope length. Protection factors: population density, plant cover, amenity value (pressure for use) and land management. Resistance factors: soil erodibility, infiltration capacity and soil management. Sumber: http://users.ictp.it/~pub_off/lectures/lns018/21Lobo.pdf

34. ERODIBILITAS TANAH The soil erodibility factor (K-factor) is a quantitative description of the inherent erodibility of a particular soil; it is a measure of the susceptibility of soil particles to detachment and transport by rainfall and runoff. For a particular soil, the soil erodibility factor is the rate of erosion per unit erosion index from a standard plot. The factor reflects the fact that different soils erode at different rates when the other factors that affect erosion (e.g., infiltration rate, permeability, total water capacity, dispersion, rain splash, and abrasion) are the same. Texture is the principal factor affecting Kfact, but structure, organic matter, and permeability also contribute. The soil erodibility factor ranges in value from 0.02 to 0.69 (Goldman et al. 1986; Mitchell and Bubenzer 1980). Sumber: http://mepas.pnnl.gov/mepas/formulations/source_term/5_0/5_32/5_32.html

35. Stewart et al. (1975) also developed a table indicating the general magnitude of the K-factor as a function of organic matter content (Pom) and soil textural class. Sumber: http://mepas.pnnl.gov/mepas/formulations/source_term/5_0/5_32/5_32.html

36. Soil ERODIBILITY Factor (K). The soil texture, and other soil characteristics, affect its susceptibility to erosion. The soil K factors were determined experimentally in test plots that were 72.6 ft long and had a uniform slope of 9%. The nomograph used to determine the K factor for a soil, based on its texture (% silt plus very fine sand, % sand, % organic matter, soil structure, and permeability. Significant disturbance and modifications of the soil obviously occurs at construction sites and care needs to be taken to ensure that the K factor is based on the actual surface soil conditions. As an example, the organic matter (decreases as the top soils are removed), permeability (decreases with compaction with heavy equipment), and soil structure (subsurface soils more massive than surface soils) could all likely change, causing the K factor to increase for a soil undergoing modification at a construction site. Sumber: http://rpitt.eng.ua.edu/Class/Erosioncontrol/Module3/Module3.htm

37. Soil ERODIBILITY Factor (K). USDA nomograph used to calculate soil erodibility (K) factor. Sumber: http://rpitt.eng.ua.edu/Class/Erosioncontrol/Module3/Module3.htm

38. Pests and diseases related to the land. The categories of problem may be listed as due to (i) wild animals, (ii) arthropods including insects and mites, (iii) parasitic nematodes, (iv) fungal pathogens, (v) bacterial pathogens, and (vi) virus diseases. In reconnaissance studies these should be considered in selecting alternative LUTs. Pests, diseases and weeds may be 'class-determining' because of the variability from one land unit to another in exposure to wild animals, in microclimate or soils, or in other land characteristics. Insect problems, particularly in cotton, have led to the failure of large irrigation schemes. Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.10%20sodicity

39. BAHAYA BANJIR In shallow water rice areas and in areas producing other crops, spasmodic floods not only affect the crop, but also damage the soil and the infrastructure, e.g. rice-field bunds, pathways, temporary and permanent houses, roads and bridges etc. Flood damage is most likely to occur on river flood plains, alluvial and coastal plains, regions with large seasonal variations in rainfall and liable to intensive rain over hours or days. The detailed pattern of incidence is thus related to landforms. In setting critical limits for flood hazard, two criteria may be used: period of inundation, and flood frequency. The period of inundation is the average number of days during the cropping season or year when the land is covered by water. This may be obtained from records or estimated. The flood frequency is the probability of occurrence of damaging floods during the year. Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.13.2%20flood%20hazard

40. Flooding hazard (including frequency, periods of inundation). A damaging flood is one that destroys or causes severe damage to the crop, land or infrastructure. Where required, a damaging flood may be defined quantitatively in terms of period of inundation and/or speed of flow or volume of discharge of moving water. The following scale can be applied quantitatively where data are available, but will usually form the basis for subjective estimation. Frequency of damaging floods: Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.13.2%20flood%20hazard

41. Storm, hail and wind hazard The exposure of land to storm and wind and the susceptibility or tolerance to these for different crops often needs assessment in land evaluation. A judgement needs to be made of the economic impact which is probable for respective land units and crops. Two aspects are the general prevalence of the hazard (e.g. wind) and the occurrence of special events such as high intensity rainfall, cyclones and hurricanes. The latter are considerations in the selection of LUTs, but the extent of the damage and the ability of the crop to survive and sustain production after the event may be aggravated at specific sites, which could be differentiated into factor ratings. Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.13.2%20flood%20hazard

42. Storm, hail and wind hazard Amongst crops there is a clear distinction between short-term crops and perennial crops. The survival of short-term crops in the event of an infrequent storm hazard is of less consequence than for tree crops and orchards which might be completely destroyed. Bananas have the capability of regrowth from underground shoots if the above ground parts of the plant are destroyed; most tree crops do not have this capability. Hail can severely damage or destroy crops in many parts of the world and may have a bearing on the crops chosen. Hail damage is often very localized. The possibility of insurance against hail damage may also affect the choice of crops. Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.13.2%20flood%20hazard

43. Frost hazard Where it occurs, frost can be an important land class-determining factor. Frost pockets occur in valley floors owing to katabatic air movements. Frost can destroy the flowers of temperate fruit crops and consequently affect yields. Rare frosts are particularly important in the case of orchards (e.g. citrus) where trees of all ages may be destroyed. Damaging frosts can be defined in terms of temperatures, duration, and periods of the year during which damage may occur using data from climatic records. Local experience is often helpful in indicating the effect of landforms (i.e. the greater incidence in valley floors and the increase in incidence with altitude). Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm#a.13.2%20flood%20hazard

44. SOIL TEMPERATURE REGIME. In soil taxonomy, soil temperature regimes are based on mean annual soil temperatures.  Soil temperatures are taken at a depth of 50 cm from the soil surface, using the Celsius (centigrade) scale.  These regimes greatly affect the use and management of soils, particularly for the selection of adapted plants. The ten soil temperature regimes are cryic, frigid, hyperthermic, isofrigid, isohyperthermic, isomesic, isothermic, mesic, pergelic, and thermic. RezimSuhu Tanah Cryic has mean annual soil temperatures of greater than 0 °C, but less than 8 °C, with a difference between mean summer and mean winter soil temperatures greater than 5 °C  at 50 cm, and cold summer temperatures. Sumber: http://passel.unl.edu/pages/informationmodule.php?idinformationmodule=1130447033&topicorder=12&maxto=13

45. REZIM SUHU TANAH The frigid soil temperature regime has mean annual soil temperatures of greater than 0 °C, but less than 8 °C, with a difference between mean summer and mean winter soil temperatures greater than 5 °C  at 50 cm below the surface, and warm summer temperatures.  The hyperthermic soil temperature regime has mean annual soil temperatures of 22 °C or more and a difference between mean summer and mean winter soil temperatures of less than 5 °C at 50 cm below the surface.  Sumber: http://passel.unl.edu/pages/informationmodule.php?idinformationmodule=1130447033&topicorder=12&maxto=13

46. REZIM SUHU TANAH The isofrigid soil temperature regime has mean annual soil temperatures of  greater than 0 °C, but less than 8 °C, with a difference between mean summer and mean winter soil temperatures of less than 5 °C  at 50 cm. below the surface, and warm summer temperatures.  The isohyperthermic soil temperature regime has mean annual soil temperatures of 22 °C or more and a difference between mean summer and mean winter soil temperatures of less than 5 °C at 50 cm below the surface.  Sumber: http://passel.unl.edu/pages/informationmodule.php?idinformationmodule=1130447033&topicorder=12&maxto=13

47. REZIM SUHU TANAH The isomesic soil temperature regime has a mean annual soil temperatures of 8 °C or more, but a difference between mean summer and mean winter soil temperatures of less than 5 °C  at 50 cm below the surface.  The isothermic soil temperature regime that has mean annual soil temperatures of 15 °C or more but, 5 °C difference between mean summer and mean winter soil temperatures at 50 cm. below the surface.  The mesic soil temperature regime has mean annual soil temperatures of 8 °C or more, but less than 15 °C, and the difference between mean summer and mean winter soil temperatures is greater than 5 °C  at 50 cm below the surface.  Sumber: http://passel.unl.edu/pages/informationmodule.php?idinformationmodule=1130447033&topicorder=12&maxto=13

48. REZIM SUHU TANAH The pergelic soil temperature regime has mean annual soil temperatures of less than 0 °C at 50 cm below the surface.   In this terperature regime, permafrost is present.ThermicThe thermic soil temperature regime has mean annual soil temperatures of 15° C or more, but less than 22 °C; and a difference between mean summer and mean winter soil temperatures of greater than 5 °C  at 50 cm below the surface. Sumber: http://passel.unl.edu/pages/informationmodule.php?idinformationmodule=1130447033&topicorder=12&maxto=13

49. Radiation energy and photoperiod. Three relevant aspects of radiation are (i) daylength, (ii) its influence on photosynthesis and dry matter accumulation in crops, and (iii) its effects on evapotranspiration. Radiation levels may also be important in the drying and ripening of crops, but this is evaluated under heading B.17. Daylength may be a relevant class-determining factor in evaluations carried out at low intensity across different latitudes as already discussed under 'Growing Period' (Tables 32 and 33). Daylength affects photoperiod-sensitive cultivars of crops such as rice, influencing floral initiation and the onset or length of vegetative and reproductive phases of growth and development. The interaction of daylength with water availability or temperature can sometimes prove 'class-determining' at project level (e.g. in influencing the flowering of sugarcane, flowering and fruiting of mangoes, and in the bulbing and ripening of onions, etc.). The influence of radiation on photosynthesis and dry matter accumulation in crops has been reviewed by Monteith (1972). Sumber: http://www.fao.org/docrep/X5648E/x5648e0e.htm

50. PHOTOPERIODISME. Photoperiodism is the physiological reaction of organisms to the length of day or night. It occurs in plants and animals. Photoperiodism can also be defined as the developmental responses of plants to the relative lengths of the light and dark periods. Here it should be emphasized that photoperiodic effects relate directly to the timing of both the light and dark periods. Sumber: http://en.wikipedia.org/wiki/Photoperiodism