Sesbania is an important green manuring crop grown under rice-wheat system that could
substitute nitrogenous fertilizer. Ho.wever, production of biomass largely depends upon its
management. A long-term soil fertility experiment has been conductf!d since 1988 at national
wheat research program, Bhairahawa to evaluate the effect nutrient {P and K) on Sesbania
biomass production and its effect on grain yield of rice and wheat and on soil properties as
well. Six different treatments including two Sesbania {with and with out P) were evaluated.
Missing nutrient {P and K) was applied to part of the plot to observe the effect of
superimpose on biomass production. Sesbania biomass declined linearly {J' = -893+ 13726
nl ••
X, x = 0.825 ) in minus P plots and biomass came down below 2 tonlha in later years.
Sesbania grown in residual P plots initially increased, however, it also showed declining
trend {Y = -270+16123X, K = 0.184"·). Application ofphosphorus toP missing treatment
increased 5-fold biomass of Sesbania than no P plots. Similarly superimpose of potassium
also increased {17%) biomass over no potassium plots. Biomass of Sesbania grown in N
plots {minus P and Kplots) correlated with rice yields {r = 0.73*), r-valuefurther increased
to 0. 78 when grown in residual P plots. Farmyard manure found to be superior over
Sesbania in producing rice-wheat grain yields and also improved soil chemical properties
compared to Sesbania. No residual effect of Sesbania was seen on wheat crop; rather wheat
yields were lower in Sesbania plot than the no Sesbania plot in later years of the experiment.
Sesbania had no effect on soil organic matter content. Growth and biomass of Sesbania was
largely limited by phosphorus followed by potassium. Sesbania biomass yield could be
reversed with the replenishment of P and K

Sesbania is an important green manuring crop grown under rice-wheat system that could
substitute nitrogenous fertilizer. Ho.wever, production of biomass largely depends upon its
management. A long-term soil fertility experiment has been conductf!d since 1988 at national
wheat research program, Bhairahawa to evaluate the effect nutrient {P and K) on Sesbania
biomass production and its effect on grain yield of rice and wheat and on soil properties as
well. Six different treatments including two Sesbania {with and with out P) were evaluated.
Missing nutrient {P and K) was applied to part of the plot to observe the effect of
superimpose on biomass production. Sesbania biomass declined linearly {J' = -893+ 13726
nl ••
X, x = 0.825 ) in minus P plots and biomass came down below 2 tonlha in later years.
Sesbania grown in residual P plots initially increased, however, it also showed declining
trend {Y = -270+16123X, K = 0.184"·). Application ofphosphorus toP missing treatment
increased 5-fold biomass of Sesbania than no P plots. Similarly superimpose of potassium
also increased {17%) biomass over no potassium plots. Biomass of Sesbania grown in N
plots {minus P and Kplots) correlated with rice yields {r = 0.73*), r-valuefurther increased
to 0. 78 when grown in residual P plots. Farmyard manure found to be superior over
Sesbania in producing rice-wheat grain yields and also improved soil chemical properties
compared to Sesbania. No residual effect of Sesbania was seen on wheat crop; rather wheat
yields were lower in Sesbania plot than the no Sesbania plot in later years of the experiment.
Sesbania had no effect on soil organic matter content. Growth and biomass of Sesbania was
largely limited by phosphorus followed by potassium. Sesbania biomass yield could be
reversed with the replenishment of P and K