EFFECT OF FARMYARD MANURE AND CHEMICAL FERTILIZER ON TOTAL NET PRODUCTION, YIELD, AND ROOT NECROMASS IN A DRYLAND RICE LENTIL AGROECOSYSTEM

Effects of farmyard manure (FYM) and chemical fertilizer on crop bioma ss [total net production (TNP)], yield, and root necromass were studie d in a tropical dryland rice-lentil rotation agroecosystem. Total net production of rice which was greater than that of lentil increased sig nificantly with exogenous nutrient inputs. During both crops abovegrou nd net production (ANP) was recorded till the final harvest but no bel owground net production (BNP) was recorded after the grain or seed-for ming stage. Compared to the control, enhancement of TNP in rice was co mparable for fertilizer (32%) and FYM (30%) treatments, but in lentil FYM showed a greater effect (43%) compared to fertilizer (29%) applica tion. Grain or seed yield accounted for about 11% of TNP in both crops . Similar to TNP, rice yield showed a greater response to fertilizer ( 50%) compared to FYM (44%) while lentil yield responded more to FYM (4 3%) than to fertilizer (21%). Farmyard manure application resulted in greater necromass accumulation compared to fertilizer application. Ric e contributed the major portion of root necromass in the crop land. Wh ile root necromass increased through the rice crop period, it decrease d consistently through that of the lentil crop.