What is manure

INTRODUCTIONOrganic manures probably found their use in fields from the time the man began ploughing soils. Soil compositions vary widely due to differences in the formation process and usually one or more, of the plant nutrients are limiting factors in the crop production. Lvosses of nutrients continually take place due to cropping, leaching, and erosion and these have to be supplemented, if soil fertility is to be maintained. The practice of application of farm yard manure (FIM) has to some extent checked the rapid deterioration in soils. In fact, as pointed 1 out by Stewart, even if all the available organic matter is applied back to the soils, there will still be scope for application of fertilizers, firstly to increase the nutrient status of the soils and secondly to maintain it at a high level of productivity* It is a sound policy, therefore, to take (-very reasonable step to ensure supply to the land, all organic waste materials likely to be of value as soil improvers and it Is equally sound and necessary to make full provision for supplementing such materials with minerals and other fertilizers which can 2-4 play an important part in the improvement of soil fertility • Maintenance of soil organic matter at a satisfactory level in cultivated soils is generally recognized as one of the rears problems in agriculture. The supply of organic residues is limited and most of these materials are oxidized rather rapidly, s Allison et al. in their studies have reported that the quantity and nature of the organic soil-colloids affect the rate of loss of carbon and the quantity of humus formed from rapidly decomposable plant materials, Montmorillonite type of clay exerts the greatest effect in holding carbon, ' This type of inorganic colloids protect proteins through the formation of organic- ' montmorillonite or organic-inorganic colloid complex. The actual role of organic matter in maintaining soil fertility has been the subject of controversy for some years, Keen6 holds the view that because of the rapid decomposition of organic matter in tropical conditions, the beneficial effect of bulky organic manures lies, not so much in securing physical improvement of soils as in supplementing plant" nutrients that are contained in the manure. It is shown that a large increase in yields are obtained by applying ashes of green manure rather than by digging in the green manure crop7*8. Q Broadbent is of the opinion that the addition of rapidly decomposable organic matter promotes bacterial growth?which helps decomposition of native organic matter. Melsted is of the view that the addition of inorganic nitrogen to IT-deficient residues does not have a beneficial effect on the amount of humus formed. But there is evidence that the use of suitable and balanced fertilizer mixtures give good crop yields comparable to those obtained by the application of a large dose of organic manures. Deterioration of soli Is found to occur in the long run by continued use of 11 inorganic fertilizer not supplemented by organic manure • Sethi3*2 has shown that significantly higher yields are obtained on the manuring of sugar cane when farmyard manure is. admixed with ammonium sulfate, Wallace and Thompson3*3 have reported that farmyard manure plus.artificial fertilizers give better results* The increase in accessory factors in tomatoes and carrots by the use of mineral fertilizers in conjunction with farmyard manure is observed by Schuplan1". From the agronomic results, use of composite fertilizer is found to have the following advantages s (i) The residual acidity of fertilizers can conveniently and effectively be controlled by the use of proper quantity of dolomitic liming material in the composite mixture• (ii) Composite fertilizers may have better physical condition and are more easily applicable than many individual fertilizer materials. (iii) Plant nutrients required in small amounts can be applied more evenly by being incorporated in composite fertilizers. Because of several advantages with the use of composite fertilizer over inorganic ones, different workers at different times...Read More