Grain yield, water productivity and nitrogen use efficiency of rice under different water management and fertilizer-N inputs in South China
Junfeng
Pana, Yanzhuo Liua, Xuhua Zhonga,∗, Rubenito M. Lampayanb,c,Grant
R. Singletonb, Nongrong Huanga, Kaiming Lianga,
Bilin Penga, Ka Tiana
Agricultural Water
Management
doi: org/10.1016/j.agwat.2017.01.013
Abstract
The
increasing scarcity of irrigation water necessitates the development of
water-saving technology inrice production. Our previous studies have shown that
“safe” alternate wetting and drying irrigation(AWD15) can effectively save
water, improve water productivity while maintain grain yield compared
tocontinuous flooding (CF) and farmer’s water management practice (FP) under a
single fertilizer-N input.The objectives of this study are (1) to investigate
the superiority of this novel water management practicecompared with FP; and
(2) to examine whether there is an interaction between water and N input andwhether
fertilizer-N input needs to be adjusted under AWD15. Two field experiments were
conductedduring the late cropping seasons of 2014 and 2015. A hybrid rice
variety Tianyou3618 was grown undertwo water management (AWD15 and FP) and four
fertilizer-N rates (0, 90, 180, 270 kg N ha−1). Grain yield,water
productivity and nitrogen use efficiency were determined. Compared to that of
FP, irrigation waterinput of AWD15 was reduced by 24.1% in 2014 and 71.4% in
2015. The number of irrigations decreasedand water productivity increased
significantly. No significant differences existed between AWD15 andFP in grain
yield, biomass, leaf area index and nitrogen use efficiency. Nitrogen input
level had significanteffects on yield, biomass, harvest index and nitrogen use
efficiency in both years. Grain yield increasedwith N rate and the optimal N
rate was 180 kg N ha−1. No significant interaction was found betweenwater and
nitrogen rate regarding biomass production and grain yield. Our results
demonstrated thatno change in N input is needed under AWD15 condition and AWD15
is advantageous over farmer’swater management practice under all N levels
investigated in South China. This is the first report on theperformance of
AWD15 under different fertilizer-N levels in South China.