Asian Research Thesis Index

Abstract

Crop yields are reduced due to limited water availability, poor soil fertility and low organic matter contents. This study comprised of four field experiments on the use of organic amendments for growing wheat cv. Bhakkar 2002 to find out their impact on crop growth, yield, nutrients contents and soil characteristics. First experiment compared the efficiency of various organic manures applied singly and in combination treatments on pre- green manured soil. The organic sources used in the experiment were: farmyard manure (FYM), poultry litter (PL), press mud (PM) and sewage sludge (SS) @ 20 t ha –1 . Two years’ data (2004-05 and 2005-06) on crop growth and yield attributes revealed that PL alone performed the best, and FYM alone gave lowest results. Combined application of PL with other organic manures gave lower growth and yield of wheat, while integration of FYM with other organic materials improved its effectiveness. Soil bulk density was not affected significantly by any treatment of organic manures. Contrastingly, FYM and PM alone or combined gave lower N contents in soil; whereas, soil P contents were greater with SS, PL alone and their integration with other organic amendments. Soil and plant K contents were higher under PL, PM and their integration with other organic amendments, while SS gave the lowest results. The highest N and P contents in wheat grain and straw were found with SS, PL alone and their integration with other organic amendments. Generally, PL alone and combined with SS performed better than all other treatments for wheat production. In Experiment-II residual effects of various organic manures treatments used in Experiment-I were evaluated for two seasons (2005-06 and 2006-07). Crop growth and yield parameters were higher with PL+PM and FYM+PM; while, FYM performed the least. Application of PL, SS alone and combined together enhanced N and P contents in soil and plants; while PM / FYM lowered them. Potassium contents in soil and plants were higher under PL, PM and their integration, while SS gave 1  the lowest contents. Residual effect of PL alone or combined with other organic manures especially SS and FYM was greater than all other treatments for wheat. Combined application of PL and FYM with other organic manures improved their effectiveness. In Experiment-III, efficiency of organic manures used as in Experiment-1 was compared on wheat straw pre-manured soil in 2005-06 and 2006-07. Data on various growth attributes of crop indicated that sole use of all the organic manures (FYM, PL, PM, SS) performed better than their combined application, and PL alone out-performed over others. However, yield and yield contributing parameters responded better to the integration of these organic amendments; among them PL+SS and PL+PM gave better results. Use of PL+PM and PM+SS lowered the soil bulk density significantly and to the maximum. Application of PL, SS both alone and combined increased N and P contents in soil and plants over others. Soil and plant K contents were highest under PL, PM alone and their integration, while SS and its combinations gave the lowest K contents. On the overall, PL used alone or in combination with other organic manures especially SS was superior to all other treatments. Fourth experiment compared the efficiency of NPK fertilizers, PL alone and other organic manures (FYM, PM, SS) used in combination with PL and with each other under different available soil moisture depletion levels (ASDLs) on wheat straw pre-manured soil during 2005-06 and 2006-07). Interactions of ASDLs and organic manures showed that PL alone and NPK fertilizer under ASDL 2 (65%) followed by PL+PM+SS gave higher growth measurements and production of wheat. It was concluded that PL whether used alone or integrated with other organic manures is the best for growing wheat in green manured as well as straw incorporated soil. Further, PL should be used at 65% ASMDL for having higher wheat production under rain-fed conditions.

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