The Comparative Studies On Yield And Resource Use Efficiency Of Different Match Cropping Patterns Of Rice And Maize In Paddy Field In South Of China

In order to excavate the production potential of the major food crops rice and maize in paddy field in South of China and increase the annual resource use efficiency, this study was conducted under high-yield cultivation conditions in Baitutan Town, Liling City in Hunan Province. The field experiment consisted of four cropping patterns:early rice-late rice(R+R), spring maize-late rice(M+R),spring maize-autumn maize(M+M) and early rice-autumn maize(R+M) and compared the annual yield, yield components, dry matter accumulation characteristics and resource use efficiency of different cropping patterns. The key outcomes are as follows.(1)The pattern (M+R) had the highest annual productivity reaching23656.0kg/hm2and increased by13.6%,18.1%and34%than patterns (R+R),(M+M) and (R+M),which the annual productivity were20819.8kg/hm2,20026.7kg/hm2and17653.6kg/hm2respectively. However, for different crop in the same planting season, the yield of maize in the pattern(M+R) increased by25.0%than the rice in the pattern(R+R) and the yield of late rice in the pattern(M+R) increased by45.2%than the autumn maize in the pattern(M+M).The annual yield of one-season rice and maize showed a trend that decreased successively as the order of spring maize, late rice, early rice and autumn maize. Therefore, different crop in different planting season lead to significant differences in annual yield.(2)The higher yield of maize in pattern(M+R) than in patterns(M+M) and (R+M) resulted from the significant increase of grain numbers per ear(421.3grains per ear) and1000-grain weight(343.9grams).And the higher yield of late rice in pattern(M+R) than of early rice in patterns(R+R) and (R+M) resulted from in significant increase of grain number per panicle(151.0grains per panicle) and seed-setting rate(85.5%).In the same planting season, the spring maize in pattern(M+R) made full use of the high efficiency of solar energy of C4plants and the dry matter reached to22254.9kg/hm2and increased by20.4%than early rice(18479.1kg/hm2) and the dry matter of late rice(22831.8kg/hm2) increased by48.1%than the autumn maize in pattern(M+M). Therefore, the higher annual dry matter production(67197.2kg/hm2) laid a high-yielding material basis for the cropping pattern(M+R).(3)The pattern (M+R) had a significant advantage than other cropping patterns in the resource use efficiency of annual abiotic stress. The total solar energy use efficiency of pattern (M+R) was1.52%and increased by11.8%,20.6%and33.3%respectively. The annual temperature production efficiency was6.63kg/hm2·℃and increased by5.7%,4.7%and8.3%respectively than patterns (R+R),(M+M) and (R+M).The annual rainfall production efficiency was4.54g/m2-mm and increased by6.6%511.3%and26.1%respectively than patterns (R+R),(M+M) and (R+M).All above had showed the high-efficiency characteristics in solar energy, temperature and rainfall of the cropping pattern(M+R).In addition, The land use rate of pattern (M+R) was68.8%and increased by1.21%,21.2%and20.1%respectively than patterns (R+R),(M+M) and (R+M).Therefore its land use period was relatively long and the use efficiency was higher.(4)The pattern (M+R) had the highest nitrogen absorption use efficiency(RE) and increased by26.0%,7.3%and30.1%respectively than patterns (R+R),(M+M) and (R+M).The nitrogen absorption use efficiency was characterized by that spring maize was higher than early than early rice and late rice was higher than autumn maize. Meanwhile the pattern (M+R) had relatively lower nitrogen partial factor productivity(PFP), agronomic efficiency (AE) and physiological efficiency (PE).