西北地区不同间套作模式养分吸收利用及其对产量优势的影响

Effects of nutrient uptake and utilization on yield of intercropping systems in Northwest China

养分吸收和利用对间套作产量优势有重要影响,而西北地区近年来发展的间套作模式中养分吸收和利用研究较少。本研究采用田间小区试验,比较了西北地区新型间套作模式玉米/马铃薯、玉米/油菜、大豆/马铃薯、大豆/油菜和马铃薯/油菜的间作优势以及成熟期养分吸收量和利用效率对间作优势的影响。结果表明,玉米/马铃薯、玉米/油菜、大豆/油菜和大豆/马铃薯4种间作模式具有间作产量优势,经济效益高于相应单作。马铃薯/油菜间作无产量优势。玉米/马铃薯、玉米/油菜、大豆/马铃薯和大豆/油菜间作体系中作物氮、磷和钾养分吸收总量分别高于相应单作10%-41%、8%-21%和11%-34%;马铃薯/油菜间作体系作物氮、磷和钾吸收量分别低于单作35%、42%和63%。玉米/油菜和大豆/油菜间作作物氮、磷和钾的利用效率分别高出相应单作10%-21%、5%-7%和15%-17%;玉米/马铃薯间作氮和钾利用效率间作比单作低3%和4%,而磷利用效率高于单作21%;大豆/马铃薯间作作物氮、磷和钾的利用效率分别比单作低15%、3%和14%;马铃薯/油菜间作氮磷利用效率间作低于单作18%和4%,钾利用效率间作高于单作20%。本研究证明并非所有间作模式都具有间作产量优势,并且间作优势主要源于养分吸收量的增加。

Nutrient uptake and utilization play an important role in yield advantage of intercropping,however,effects of nutrient and utilization on yield advantage of new intercropping systems are rarely explored in Northwest China,a field experiment was carried out to investigate effects of nutrient uptake and utilization on yield advantage of maize/potato,maize/rapeseed,soybean/potato,soybean/rapeseed and potato/rapeseed in Northwest China.The results showed that maize/potato,maize/rapeseed,soybean/potato and soybean/rapeseed intercropping systems had yield advantages with a land equivalent ratio（LER）〉1,and economic benefits was higher than those in the corresponding sole cropping systems,potato/rapeseed intercropping systems had a yield disadvantage with a land equivalent ratio（LER）〈1.Nitrogen（N）,phosphorus（P）and potassium（K）uptake of maize/potato,maize/rapeseed,soybean/potato and soybean/rapeseed intercropping systems was increased by 10%-41%,8%-21% and 11%-34% compared to the weighted means of corresponding sole cropping systems.In contrast,potato/rapeseed intercropping systems decreased N,P and K uptake by 35%,42% and 63%,compared with corresponding weighted mean of sole cropping systems.N,P and K utilization efficiency by maize/rapeseed and soybean/rapeseed intercropping systems were 10%-21%、5%-7% and 15%-17% higher than the weighted means of sole cropping systems.N and K utilization efficiency in intercropping systems of maize/potato was 3% and 4%lower than those in the corresponding sole cropping systems.P utilization efficiency in maize/potato intercropping was 21% higher than that in the corresponding sole cropping systems.The N,P and K utilization efficiency in soybean/potato intercropping systems was reduced by 15%、3% and14%,compared to the weighted means of the sole cropping systems.N and P utilization efficiency in potato/rapeseed intercropping was 18% and 4%lower than that in the corresponding sole cropping systems.K utilization efficiency in maize/potato intercropping was 20% higher than that in the corresponding sole cropping systems.Not all intercropping systems have yield advantage,and yield advantage of intercropping was mainly attributed to enhanced nutrient uptake efficiency.