Intensification and no till system are efficient nitrogen allocators in rice crops

Abstract

Nitrogen is one of the yield-limiting nutrients for the growth of rice plants. The study emphasizes on utilization of nitrogen by the four varieties of rice plants (viz. var. MTU 1010, var. IET 4786, var. IET 17430, and var. IET 9947) under system of rice intensification (SRI), zero tillage (ZTL), and conventional (CVN) method of cultivation in India. Results showed that plants under SRI and ZTL cultivation have significantly higher capacity (55% and 39%, respectively) of nitrogen uptake (kg ha−1) at maturity than CVN cultivation. The yield ranged from 9.15 ± 2.33 to 13.53 ± 1.94 t ha−1, and 3.26 ± 0.93 to 5.05 ± 1.03 t ha−1 in the SRI and ZTL, respectively which was higher as compared to CVN that was 2.84 ± 0.72 to 5.02 ± 0.32 t ha−1. Results also showed that plants under SRI and ZTL cultivation have higher values for nitrogen use efficiency (NUE) indices than CVN plants (p < .05). The agronomical efficiencies (AE) were 111.74 ± 31.27, 37.92 ± 6.57 and 38.13 ± 11.17 for SRI, CVN and ZTL respectively. The physiological efficiencies (PE) were 141.39 ± 4.50, 220.31 ± 10.32, 207.59 ± 11.07 for SRI, CVN, and ZTL, respectively. In case of nitrogen harvest index (NHI), the values were 0.54 ± 0.03, 0.26 ± 0.03, 0.15 ± 0.04 for SRI, CVN, and ZTL, respectively. Thus, improved farming practices such as SRI or ZTL need to be introduced over the CVN farming technique to increase rice yields, and ensure efficient use of applied nitrogen.