Soil

Fertilizer

FERTILIZER RECOMMENDATION FOR MAJOR CROPS   N P K PADDY (kg/ha) Upland(Modan) PTB 28,29 and 30 High-yielding short duration varieties 40 60 20 30 30 30 Wet land (All regions) High-yielding short duration varieties High-yielding medium duration varieties Local varieties H4 Mashuri 70 90 40 70 50 35 45 20 45 25 35 45 20 45 25 COCONUT (Adult palm)kg/palm/annum. General recommendation (a) Average management (b) Good Management (c) For reclaimed clayey soils (as in Kuttanad) 0.34 0.50 0.25 0.17 0.32 0.35 0.68 1.20 0.90 Hybrid and high yielding palm (a) For irrigated areas (b) Rainfed 1.00 0.50 0.50 0.32 2.00 1.20         RUBBER From 1st year to 4th year :-10:10:4:1.5 NPK Mg mixture at the following rates: 3rd Month 225g / plant 9th Month 450g / plant 15th Month 450g / plant 21st Month 550g / plant 27th Month 550g / plant 33rd Month 450g / plant 39th Month 450g / plant From 5th year till tapping begins 12:12:12 NPK Mixture @ 125 kg /ha during April – May and September – October (Where mulching was practiced during initial years) 15:10:6 NPK Mixture @ 200 kg /ha during April – May and September – October (Where mulching was not practiced during initial years) Mature Rubber under tapping 10:10:10 NPK Mixture @ 300 kg /ha or 900 g / plant March -April or 15:15:15 NPK Mixture @ 200 kg /ha or 17:17:17 NPK Mixture @ 175 kg /ha or 19:19:19 NPK Mixture @ 160 kg /ha   N P K  TAPIOCA (kg per hectare) H.97, H.226 75 75 75       H.165, H.1687, H.2304 100 100 100       M4 and Local 50 50 50 SWEET POTATO (kg/ha ) 75 50 75 SESAMUM (kg/ha ) 30 15 30 GROUNDNUT (kg/ha ) 10 75 75 BANANA (g/plant)       Nendran (irrigated ) 190 115 …

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Problem Soils of Kerala

Problem Soils and Management Acidity, salinity, water logging and poor physical properties are the major problems that exist in the state. 1. Kuttanad arid soils Very strong soils (with pH less than 3.0) that are seen in Kuttanad areas are kept submerged in water for major part of the year as they lie below sea level: So, this area faces problems of floods and water stagnation. Toxicities of iron, aluminium, manganese are observed and the availability of calcium, magnesium, potassium is low. The organic matter rich soils of Kuttanad faces drainage problem apart form acidity. Occurrence of heavy rainfall damages the bunds while flooding results in severe crop damage. Management Research on soil acidity and plant growth, water management studied has to be intensified and proper agro-techniques for this area have to be framed. Apart from this, as rice is the major crop that is taken up for cultivation, certain precautions certainly helps to increase the productivity. Rice season starts by September-October and ends by January-February. Seeds should be sown only after dewatering the area. The soil should not be allowed to dry up after the seeds are sown. Formation of deep cracks and hand pans can be eliminated by submerging the field. 2. Kole soils Kole soils are also water-logged in nature like Kuttanad soils covering 11,000 ha in Trichur and Malappuram. The soils are shallow, acid saline due to intrusion of water, the characteristic feature that makes these soils to differ from Kuttanad acid soils. The soil is hard and brittle, poor in fertility.  Management Intrusion of seawater is to be prevented and heavy doses of manures and fertilizers are to be applied. By proper soil and water management suitable cropping system is to be adopted. 3. Coastal sandy soils . Poor fertility, high water table, improper drainage …

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Topography

Based on the physical features Kerala is classified as given below High Ranges (above 750m MSL) The mountainous land (elevation: 750 m to 2500 m above MSL) along the Western Ghats with jutting rocks and loamy soils constitutes the High Ranges. The two districts of Wayanad and Idukki and the eastern parts of the other districts bordering the Western Ghats come under this class. Most of the reserve forests of the state are in this tract. The important peaks in the Western Ghats are Anamudi (2690 m), Mukunti (2550m) and Nilgiris (2470m). The Palakkad gap with a width of 32 km is the largest pass in the Western Ghats. In addition, there are a few other passes in the Ghats such as Aramboli, kumali, kambam, Thevaram,Bodinaikannuur, karkken, periya and Perambadi. Plantations of tea, coffee, rubber and cardamom dominate the High Range region. High land (75-750m above MSL) This hilly tract on the western side of Western Ghats, comprising about 43 per cent of the land and supporting 14 per cent of the population, is covered with forests and small streams. Plantations of tea, coffee, cardamom and rubber are common. The soils are generally forest loams, which show wide variation in depth with a very high percentage of organic matter. A large percentage of the population of hill tribes lives in this region. Midland (7.5-75m above MSL) The midland plains comprising about 42 per cent of the land mass have an undulating terrain intersected by numerous rivers, small hills and valley and 59 per cent of the state’s population live in this tract. The soil is mainly laterite and supports an intense diversity of seasonal, annual and perennial crops like rice, sugarcane, tapioca banana, ginger, coconut, arecanut, pepper, cashew, rubber etc. Lowland (Up to 7.5m above MSL) The lowland bordering the …

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Soil Conservation

Soil conservation is an effort made by man to prevent soil erosion in order to retain the fertility of soil. It may not be possible to stop soil erosion entirely. Any erosion such as gullies already formed should be tackled by construction of dams or obstructions. Ploughing and tilling of land should be done along contour levels so that the furrows run across the slope of land. Bunds should be constructed according to contours. Trees reduce the force of straight winds and obstruct blowing away of dust particles. Plants, grass and shrubs reduce the speed of flowing water. Therefore, such vegetable cover should not be removed indiscriminately, where it dose not exist, steps should be taken to plant it. Natural vegetation cover prevents soil erosion in three ways : (i) The roots of plants bind together the particles of soil; (ii) Plants check the force of wind so that it cannot blow away the soil particles; and (iii) Plants lessen the force of rain as it reaches the ground. Measures for Soil Conservation (i) Planting cover crops such as grasses, on uncultivated land. Trees should be Planted along hill slopes. (ii) Adoption of correct farming techniques such as contour ploughing and strip Cropping,. Strip cropping is the practice of planting alternate rows of close growing plants such as beans and peas, with open growing crops such as corn. This practice prevents wind erosion. (iii) Terracing, the practice of cutting steps in hillside, to create level land for Cultivation. (iv) Construction of check dams on steep slopes which prevent gully erosion and Spread gullies. (v) Creation of wind breaks by planting lines of trees, hedges or fences which Obstruct the path of wind thereby reducing its speed and hence reducing soil erosion. (vi) Controlling grazing of pastures. (vii) Suspending cultivation for one season and more, so …

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Soil Erosion

Soil erosion – is the process of detachment and displacement of soil particles from land surface. Agencies involved – water, wind, sea waves and animals. 2 broad categories – (i) The Natural erosion or the geologic erosion or the normal erosion; (ii) Accelerated erosion or soil erosion – By soil erosion we mean accelerated soil erosion only. Reasons (1) Destruction of forests, (2) unscientific cultivation practices, (3) Heavy grazing in pasture and grass lands. Harmful effects – (1) Convert the fertile lands to barren and unproductive, (2) causes frequent floods and diversion of course of flow of rivers through fertile river banks due to deposition of soil in river basins, (3) silting of dams due to deposition of sand and silt. Types of Erosion – (1) Rainwater erosion includes – splash erosion, sheet erosion, hill erosion and gully erosion – out of these Gully erosion is the most serve for. (2) Land slides erosion – Earthquakes, heavy rainfall, etc., are the major factors – Heavy destruction of forests also (takes places is sloppy and mountainous areas). (3) Stream Bank Erosion – due to torrential rains in hilly areas causes flooding of rivers and streams causing large scale erosion throughout the stream banks. (4) Sea shore erosion – due to turbulent waves in the sea during heavy rains and winds. (5) Wind erosion – in low rainfall areas – due to strong winds – soil particles are deposited on fertile soils of far of places. Causes expansion of deserts to fertile areas. Winds cause movement of soil particle in 3 ways – (i) Saltation, (ii) Suspension, (iii) surface creep. Saltation – soil particles having a size of between 0.1 to 0.5 mm diameters are directly hit by wind which lead to a bouncing action of the particles- this bouncing action is …

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Soil Testing

Soil Testing Facilities in Kerala There are 14 soil-testing labs in Kerala, i.e., one for each district. A central soil testing labs is functioning at Parottukonam, Nalanchira to supervise, coordinate and control the activities of the different soil testing labs in the state. There are 9 mobile soil-testing labs with a testing capacity of 50 samples per day one each in 9 districts (except districts of Ernakulam, Pathanamthitta, Idukki, Wayanad and Kasargodu). Soil Test Crop Response correlation Studies Interpreted S.T. Data – best basis for fertiliser recommendation. But the response of the crop depends on other factor like plant population, crop variety, soil moisture, etc.- many methods were suggested to improve ST interpretations. The all India Coordinated Project for investigation on ST – crop response – started in 1967. The studies have indicated significant regression equation for different soil types for predicting crop response and for preparing suitable fertiliser schedules based on ST data. The purpose of ST crop response studies is securing and selecting the best ST method and the calibration of ST values for fertiliser recommendation – the studies enable to know the type of response curve operating in a set of soil-crop-agro-climaric condition, e.g., of each curves – linear, mitscherlich-bray, sigmoid, etc – curves are useful to determine fertiliser does to obtain economic yield – different approaches – critical level approach, percentage yield approach, targeted yield/prescription method . Soil Test Summaries and Soil Fertility Map Soil test data can be summarized to provide information on overall fertiliser requirements for specific areas and on the kinds of fertiliser materials and mixture most suitable for those areas. Helpful for planners and administrators in determining policies of fertilizer production, distribution and consumption – useful for researchers also – can be prepared soil wise, village wise, block wise or district wise. …

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Reclamation

Soils which contain high levels of particular clays, such as smectites, are often very fertile. For example, the smectite-rich clays of Thailand’s Central Plains are among the most productive in the world. Many farmers in tropical areas, however, struggle to retain organic matter in the soils they work. In recent years, for example, productivity has declined in the low-clay soils of northern Thailand. Farmers initially responded by adding organic matter from termite mounds, but this was unsustainable in the long-term. Scientists experimented with adding bentonite, one of the smectite family of clays, to the soil. In field trials, conducted by scientists from the International Water Management Institute in cooperation with Khon Kaen University and local farmers, this had the effect of helping retain water and nutrients. Supplementing the farmer’s usual practice with a single application of 200 kg bentonite per rai (6.26 rai = 1 hectare) resulted in an average yield increase of 73%. More work showed that applying bentonite to degraded sandy soils reduced the risk of crop failure during drought years. In 2008, three years after the initial trials, IWMI scientists conducted a survey among 250 farmers in northeast Thailand, half of whom had applied bentonite to their fields. The average improvement for those using the clay addition was 18% higher than for non-clay users. Using the clay had enabled some farmers to switch to growing vegetables, which need more fertile soil. This helped to increase their income. The researchers estimated that 200 farmers in northeast Thailand and 400 in Cambodia had adopted the use of clays, and that a further 20,000 farmers were introduced to the new technique. If the soil is too high in clay, adding gypsum, washed river sand and organic matter will balance the composition. Adding organic matter to soil which is depleted in nutrients and too high in sand will boost its quality.

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Degradation

Here, land degradation refers to a human-induced or natural process which impairs the capacity of land to function. Soils are the critical component in land degradation when it involvesacidification, contamination, desertification, erosion or salination. While soil acidification is beneficial in the case of alkaline soils, it degrades land when it lowers crop productivity and increases soil vulnerability to contamination and erosion. Soils are often initially acid because their parent materials were acid and initially low in the basic cations (calcium, magnesium, potassium and sodium). Acidification occurs when these elements are removed from the soil profile by normal rainfall or the harvesting of forest or agricultural crops. Soil acidification is accelerated by the use of acid-forming nitrogenous fertilizers and by the effects of acid precipitation. Soil contamination at low levels is often within soil’s capacity to treat and assimilate. Many waste treatment processes rely on this treatment capacity. Exceeding treatment capacity can damage soil biota and limit soil function. Derelict soils occur where industrial contamination or other development activity damages the soil to such a degree that the land cannot be used safely or productively. Remediation of derelict soil uses principles of geology, physics, chemistry and biology to degrade, attenuate, isolate or remove soil contaminants to restore soil functions and values. Techniques include leaching, air sparging, chemical amendments, phytoremediation, bioremediation and natural attenuation. Desertification is an environmental process of ecosystem degradation in arid and semi-arid regions, often caused by human activity. It is a common misconception that droughts cause desertification. Droughts are common in arid and semiarid lands. Well-managed lands can recover from drought when the rains return. Soil management tools include maintaining soil nutrient and organic matter levels, reduced tillage and increased cover. These practices help to control erosion and maintain productivity during periods when moisture is available. Continued land abuse during droughts, however, increases land degradation. Increased population and livestock pressure on marginal lands accelerates desertification. Erosion of soil is caused by wind, water, ice and movement in response to gravity. Although the processes may be …

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USDA soil taxonomy

A taxonomy is an arrangement in a systematic manner. Soil taxonomy has six categories. They are, from most general to specific: order, suborder, great group, subgroup, family and series. The soil properties that can be measured quantitatively are used to classify soils. A partial list is: depth, moisture, temperature, texture, structure, cation exchange capacity, base saturation, clay mineralogy, organic matter content and salt content. In the United States, soil orders are the top hierarchical level of soil classification in the USDA soil taxonomy . The names of the orders end with the suffix -sol. There are 12 soil orders in Soil Taxonomy: The criteria for the order divisions include properties that reflect major differences in the genesis of soils. Alfisol – soils with aluminium and iron. They have horizons of clay accumulation, and form where there is enough moisture and warmth for at least three months of plant growth. They constitute 10.1% of soils worldwide. Andisols – volcanic ash soils. They are young and very fertile. They cover 1% of the world’s ice-free surface. Aridisol – dry soils forming under desert conditions which have fewer than 90 consecutive days of moisture during the growing season. They include nearly 12% of soils on Earth. Soil formation is slow, and accumulated organic matter is scarce. They may have subsurface zones of caliche or duripan. Many aridisols have well-developed Bt horizons showing clay movement from past periods of greater moisture. Entisol – recently formed soils that lack well-developed horizons. Commonly found on unconsolidated river and beach sediments of sand and clay or volcanic ash, some have an A horizon on top of bedrock. They are 18% of soils worldwide. Gelisols – permafrost soils with permafrost within two metres of the surface or gelic materials and permafrost within one metre. They constitute 9.1% of soils worldwide. Histosol – organic soils, formerly called bog soils, are 1.2% of soils worldwide. Inceptisol – young soils. They have subsurface horizon formation but show little eluviation and illuviation. They …

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Classification

Soil is classified into categories in order to understand relationships between different soils and to determine the suitability of a soil for a particular use. One of the first classification systems was developed by the Russian scientist Dokuchaev around 1880. It was modified a number of times by American and European researchers, and developed into the system commonly used until the 1960s. It was based on the idea that soils have a particular morphology based on the materials and factors that form them. In the 1960s, a different classification system began to emerge which focused on soil morphology instead of parental materials and soil-forming factors. Since then it has undergone further modifications. The World Reference Base for Soil Resources (WRB) aims to establish an international reference base for soil classification.

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