施肥模式对菜-稻轮作周年氮素吸收及产量的影响

Effects of fertilization strategies on annual nitrogen uptake and crop yield in vegetable-rice rotation systems

为探明不同施肥模式对菜-稻轮作体系周年氮素吸收及其产量的影响,以长期定位试验中菜-菜-稻轮作和菜-菜-菜轮作各季作物为研究对象进行田间试验。2种轮作体系分别采用推荐施肥和习惯施肥2种施肥模式,于2020—2022年对各季作物氮含量和产量进行测定,研究不同施肥模式和轮作下各季作物周年氮素吸收积累量、氮肥偏生产力及其对产量效益的影响。结果表明,2个轮作周年内菜-菜-稻轮作方式下推荐施肥模式第二季作物(芥菜)和第三季作物(水稻)氮素年均吸收积累量为415.71 kg/hm^(2),显著高于习惯施肥模式(381.43kg/hm^(2))。第一和第二轮作周年,不同轮作施肥方式下四季豆作物的氮素收获指数为0.61~0.65,各处理之间无显著差异;推荐施肥处理水稻作物氮素收获指数分别为0.72和0.73,显著高于习惯施肥处理(0.62和0.62)。通过各季作物氮素吸收量与产量的相关分析表明推荐施肥处理能够提高作物氮素吸收利用率。菜-菜-稻轮作结合推荐施肥处理的年均产投比(1.79)高于习惯施肥处理(1.47),菜-菜-菜轮作结合推荐施肥处理的年均产投比(1.56)高于习惯施肥处理(1.36)。因此,推荐施肥处理作物的周年氮素吸收积累量和产量均高于习惯施肥,该施肥模式有利于菜-菜-稻轮作方式实现作物高产和氮肥高效利用,可获得较好的经济效益。

This study investigated the impacts of various fertilization strategies on the annual nitrogen uptake and crop yield in vegetable-rice rotation systems.Field experiments were conducted on crops across different seasons under both vegetablevegetable-rice and vegetable-vegetable-vegetable rotations within a long-term positioning test.Two fertilization strategies were established in the two crop rotation system:recommended fertilization and practice fertilization.Nitrogen content and crop yield were measured for each season from 2020 to 2022,providing a basis for understanding differences in annual nitrogen uptake and accumulation,nitrogen fertilizer production,and their effects on economic benefits and crop yield under varying fertilization strategies and rotations.The results revealed that the recommended fertilization strategy led to a higher average annual nitrogen uptake and accumulation in the second(mustard leaf)and third(rice)crop seasons over the two rotation years,with a value of 415.71 kg/hm^(2).This was notably higher than the 381.43 kg/hm^(2) achieved under the practice fertilization strategy.The nitrogen harvest index for kidney bean crops ranged between 0.61 to 0.65 on the first and second rotation anniversaries,and no significant differences were found between the different treatments.In contrast,the nitrogen harvest index for rice crops was significantly improved with the recommended fertilization strategy,with values of 0.72 and 0.73 for the first and second rotation anniversaries respectively.This showed considerable improvement over the practice fertilization strategy,which only achieved values of 0.62 for both rotation anniversaries.It was found that the recommended fertilization strategy significantly improved the nitrogen uptake of the third crop in both crop rotation methods.Furthermore,a correlation analysis between nitrogen uptake and crop yield suggested that the recommended fertilization strategy enhanced crop nitrogen uptake and utilization efficiency.The recommended fertilization strategy,combined with a vegetable-rice rotation,resulted in a higher annual output-to-input yield ratio of 1.79,compared to the value of 1.47 achieved with practice fertilization.Similarly,the average annual output-to-input yield ratio for the vegetable-vegetable rotation was higher when using the recommended fertilization strategy(1.56),compared to the practice fertilization strategy(1.36).The findings indicated that the recommended fertilization strategy resulted in a higher annual nitrogen uptake,accumulation,and crop yield compared to practice fertilization.This fertilization model could improve crop yield and nitrogen fertilizer efficiency in vegetable-rice rotations,leading to superior crop yield benefits.