Judicious use of organic manures and inorganic fertilizers for sustaining productivity and fertility dynamics under rice-maize and rice-groundnut cropping systems.

摘要

Rice yield was highest (71.64 q ha-1), where 50 per cent NPK was applied through inorganic source and 50 per cent N through glyricidia (T₁₀), followed by 50 per cent RDF+50 per cent N through FYM (T₈), 75 per cent RDF+25 per cent N either through glyricidia (T₁₁) or FYM (T₉). The grain yield of maize in rabi season was higher (44.43 q ha-1) when 100 per cent NPK was applied through inorganic source (T₉) preceded with application of NPK 75 per cent through inorganic and 25 per cent through organic to the rice crop in rice-maize sequence, whereas the pod yield of groundnut was higher (22.59 q ha-1) when 75 per cent NPK was applied through inorganic source (T₉) with application of NPK 50 per cent through inorganic and 50 per cent through organic to the preceding rice crop in rice-groundnut sequence. Combined grain yield of rice and maize was the highest where 50 per cent RDF+50 per cent N through green manure (glyricidia) was applied to rice and 75 per cent RDF to maize crop followed by 75 per cent RDF+25 per cent N through glyricidia to rice and 100 per cent RDF to maize. The results further indicated that combined application of organic manures and chemical fertilizers i.e. 50 per cent RDF+50 per cent N through FYM (T8) as well as 75 per cent RDF+25 per cent N through FYM (T9) recorded the lowest value of bulk density and the highest value of water holding capacity compared to 100 per cent RDF. There was increase in bulk density after harvest of maize due to continuous application of chemical fertilizers alone, whereas after harvest of groundnut, bulk density was more or less maintained near its initial value. Thus, use of FYM or green manure to the extent of 50 per cent of recommended with 50 per cent NPK through fertilizers to rice and 75 per cent recommended NPK to succeeding maize and groundnut is a judicious blend to maintain soil fertility and desirable soil physical condition and at the same time sustain crop productivity under rice-maize and rice-groundnut sequences in South Konkan region.