Background and aims Nitrogen (N), phosphorus (P), potassium (K), sulphur (S), zinc (Zn) and boron (B) nutrition of the lentil-mungbean-T. aman rice system are important for increasing system productivity and improving soil fertility. Experiments on lentil-mungbean-T. aman rice cropping system were conducted in terrace soils of Gazipur, Bangladesh to measure the system yields, nutrient concentration, uptake and apparent balances.Methods We considered four fertilizer treatments viz. absolute nutrient control (T1); farmer’s practice (T2); AEZ basis fertilizer application (T3) and soil test basis fertilizer application (T4). The treatments were compared in a randomized completely block design with three replications over two consecutive years. Results The average yields of lentil, mungbean and T. aman rice ranged from 891 to 1341 kg ha-1, 1006 to 1494 kg ha-1 and 3478 to 4526 kg ha-1, respectively showing T4 as the best treatment. Soil test basis fertilizer application (T4) exhibited the highest nutrients uptake by all tested crops. The apparent balance of N and K was negative; however it was less negative for T2 and T3 treatment. The apparent P balance was positive in T2, T3 and T4 but negative in T1. Positive S balance observed in T3 &T4 but negative in T1 and T2. Zinc and B balance in the system was positive in case of T3 and T4.Conclusion Considering highest yield, gross margin and soil fertility have been recommended that the soil test basis fertilizer application is profitable for lentil-mungbean-T.aman rice cropping system in terrace soils of Bangladesh.Future research The study clearly indicate an opportunity for the re-adjustment of the N, P, K, S and micronutrients (Zn & B) fertilizer doses for the different rice-based cropping systems in different agro-ecological zone of Bangladesh.
Keywords: System yields, lentil-mungbean-T. aman rice, nutrient concentration, nutrient uptake and balance, terrace soil
