Biomass and nitrogen accumulation of three green manure crops as affected by soil moisture, seed rate and duration of cultivation
1993
Manandhar, Ramita
Study was conducted on biomass and nitrogen accumulation of three green manure crops as affected by soil moisture, duration of cultivation and seed rate, in acid sulphate soil of Bangkok plain from February to April in 1993. The three green manure crops grown were Crotalaria juncea, Sesbania rostrata and Aeschynomene afraspera. Four soil moisture regimes were maintained by irrigating at 5 days, 15 days and 30 days interval and no irrigation, control. 30 day, 45 day and 60 day were the three durations of cultivation. 2 millions and 4 millions/ha were the 2 levels of plant densities. The overall performance of Crotalaria has been shown to be significantly better among the three crops in terms of biomass production and nitrogen accumulation. Under soil moisture stress conditions, Crotalaria continues to be superior over the other two crops in terms of biomass and nitrogen accumulation. An increase in moisture stress has decreased the biomass and nitrogen accumulation efficiency in all the crops in a significant manner. A single irrigation did not produce any significant effect over the control for any green manure crop. Crotalaria was observed to have rapid initial growth in comparison to the other two crops. An increase in the seed rate raised the plant population per unit area for all the three crops. However, in terms of nitrogen and biomass accumulation, the seed rate seems to have significant effect only in case of Aeschynomene.
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