Effect of different rates of application of organic and nitrogen fertilizers in a rice-based cropping system

Abstract

SUMMARYThe effect on soil fertility and crop performance of different organic fertilizers; paddy straw (PS), farmyard manure (FYM), water hyacinth compost (WHC) and tank silt (TS), at different rates of application and in combination with N fertilizer, was studied in a rice-based cropping system on an acid lateritic soil at Kharagpur, India, during 1985/86. Organic manuring of wet-season rice (first crop) with 5 t PS/ha 10 days before transplanting and 10 t FYM or 10 t WHC/ha at transplanting increased grain yield as much as the application of 30 kg N/ha. Increasing the rates of FYM and WHC application up to 15 t/ha increased yield but increasing the rate of PS beyond 5 t/ha did not. Response to increasing amounts of N was not linear; there was a significant increase up to 90 kg N/ha and a decrease when N was applied in conjunction with organic fertilizers. There was a significant increase in the N uptake of the rice but a decrease in the recovery of applied fertilizer N with the application of increasing rates of organic and N fertilizer.The organic C content of the soil after the rice harvest increased significantly after PS application, whereas there was more available N after WHC and FYM. Increasing the rate of application of PS up to 15 t/ha increased organic C but not available N. Mineral N fertilizer had little effect on fertility build-up. Grain yields of wheat and gram (Cicer arietinum), grown after rice without any additional fertilizer, increased significantly. The residual N effect of the previous crop on wheat or gram yield was small and adding fertilizer directly is considered essential for higher productivity in these crops in a rice-based cropping system.

Growth, yield and NPK uptake by maize with complementary organic and inorganic fertilizers.

“…The potential of cow dung, poultry droppings, refuse compost and farmyard manure as suitable soil amendments in the tropics has been reported [1,2,3,4]. Application of organic materials as fertilizers provides growthregulating substances and improves the physical, chemical and microbial properties of the soil [5,6,7,8]. Sole use of organic manures to sustain cropping has, however, been reported inadequate, as they are required in rather large quantities to meet crops' nutrient requirements because of their relatively low nutrient content [9].…”

Maize growth, yield and soil nutrient changes with N-enriched organic fertilizers

“…The need to use renewable forms of energy has revived the use of organic fertilizers worldwide. Nutrients contained in organic manures are released more slowly and are stored for a longer time in the soil, thereby ensuring a long residual effect [2], supporting better root development, leading to higher crop yields [3].Improvement of environmental conditions and public health as well as the need to reduce costs of fertilizing crops are also important reasons for advocating increased use of organic materials [4].The soil fertility status is improved by activating the soil microbial biomass [5].To meet crops' nutrient supply, organic fertilizers are, however, required in rather large quantities. Application of organic manures sustains cropping systems through better nutrient recycling [6].Application of organic manures plays a direct role in plant growth as a source of all necessary macro and micronutrients in available forms during mineralization, thereby improving both the physical and the biological properties of the soil [7].Organic manures decompose to give humus which plays an important role in the chemical behaviour of several metals in soils through the flavonic and humic acid contents, which have the ability to retain the metals in complex and chelate forms [7].Organic manures also improve the water holding capacity of the soil; improve the soil structure and the soil aeration [5].The benefits derivable from the use of organic materials have however not been fully utilized in the humid tropics.…”

Different fertilizer types affected nitrogen and carbon cycling in eroded and colluvial soils of Southern Ecuador

“…This is corroborated by Rousk et al [68] who reported that a higher pH value had a positive effect on the bacterial diversity and diverse effects on the abundance. In addition, nutrients in organic manures are not only released more slowly but they also persist in the soil for a longer period and for this reason ensure a longer residual effect compared to non-organic fertilizers [69,70].…”