Manures nutrients

Kellogg, R.L. Lander, CH. Moffit, D.C Gollehon, N. Manure nutrients relative to the capacity of cropland and pastureland to assimilate nutrients Spatial and temporal trends for the United States. US Department of Agriculture, National Resource Conservation Center, Economic Research Service, Publication number NPS-00-0579. 

Fertilization using animal products has been practiced since ancient times. Animal manure returns nutrients to the soil, replenishing elements that are depleted as crops are grown and harvested. It is likely that the use of animal fertilizers quickly followed the domestication of goats, sheep, and cattle. 

Adequate levels of lime, phosphate and potash in the soil are especially important for organic dairy farmers, because these nutrients are essential for healthy white clover. The supply of these nutrients and general manure strategy is covered fully by Newton (1993). 

Poultry manure is another valuable source of nutrients to the organic farmer, but it must come from an ethical system. 

The three most important constituents of FYM are nitrogen, phosphate and potash. Additionally, there are the bulky organic parts derived mainly from the straw and the part of the food that has resisted digestion. Granstedt (2002) showed that the majority of the N (about 90%) in farmyard manure served to maintain the soil humus store and the long term capacity to supply nutrients. 

The values quoted above are for FYM from overwintered cattle, but the method of housing influences nutrient loss. With cattle in covered yards sufficient bedding must be used to absorb the liquid manure and there is little or no drainage the dung is kept well compressed by the animals and fermentation is reduced to a minimum. Under such conditions very little loss takes place. 

Composted dung is richer in nutrients and more active, provided it has been properly made, than comparatively fresh material that has not decomposed. However, in ordinary practice, manure cannot be rotted or stored without serious loss. Although well-rotted manure may contain more plant food than an equal weight of fresh manure, a given quantity of fresh manure will contain more plant food than composted manure that has been stored. 

Although stockless systems can be practised on arable farms, by the use of green manures to maintain soil nutrient status, the need for the addition of animals as a source of recycled excreta, and as graziers, has long been recognised. At the time of the golden hoof, field owners paid shepherds for the use of their sheep, if only to have them penned up on a particular field overnight. 

By housing cattle overwinter and composting the farmyard manure, the organic farmer has ready access to a balanced fertiliser that can be spread where most required. The grazing animal does not actually import fertility onto the farm but it does recycle nutrients where it grazes and provides a source of manure when housed. This is as true of sheep, pigs and poultry as of cattle. The only problem with outdoor pigs is that they tend to rip up pastures. 

Juarez-Rodriguez et al. applied the sludge derived from anaerobically digested cow manure in the production of biogas (methane-air), to maize (Zea mays L.) cultivated in a nutrient-low, alkaline-saline soil with EC 9.4 dS m 1 and pH of 9.3. The results showed that the C02... 

Cultivation dependent on Technique, energy, nutrients Weather, labour, manure... 

Application of animal manures to soil serves as an important element of nutrient management. In addition to nutrients and the organic carbon recycled to maintain or increase soil organic matter content, which is a key element... 

Tarkalson DD, Jolly VD, Robbins CW, Terry RE (1998) Mycorrhizal colonization and nutrient uptake of dry bean in manure and compost manure treated subsoil and untreated top and subsoil. J Plant Nutr 21 1867-1878... 

The transition from conventional to organic and low-input farming is accompanied by changes in an array of soil chemical properties and processes that affect soil fertility. Fundamental differences, both qualities and quantitative, in the flow and processing of nutrient result from the use of cover crops, manure and compost applications, and reduction or elimination of synthetic fertilizers and pesticides. These changes affect nutrient availability to crops either directly by contributing to nutrient pools or indirectly by influencing the soil chemical and physical environment. 

---