陕西关中不同年代小麦品种产量及氮素吸收利用对土壤肥力的响应

【目的】探讨陕西关中地区小麦品种演替过程中产量及氮效率对土壤肥力的响应。【方法】以20世纪80年代至今关中冬麦区3个代表性小麦主栽品种为材料,以33年长期不同施肥处理构建的土壤肥力水平梯度为平台,研究品种演替和土壤肥力及其交互对作物产量、氮利用效率的影响。供试品种有20世纪80年代品种小偃6号、90年代末品种小偃22和近年品种西农979。长期施肥包括6个处理:不同水平的氮磷化肥配施(N1P1和N2P2)、有机肥与无机肥配施(M1N1P1、M1N2P2、M2N1P1和M2N2P2),以不施肥为对照(CK)。【结果】在各个肥力水平土壤上,籽粒产量及收获指数均随小麦品种更替而呈现增加的趋势,尤其在高肥力土壤上更为明显。土壤肥力水平的提高显著提高了小麦籽粒产量,其中西农979增产幅度最大(151.0%—610.5%),其次为小偃22(127.9%—349.7%),小偃6号增幅最低(148.1%—341.8%)。土壤肥力与品种对小麦籽粒产量及收获指数有显著的交互作用,低肥力条件下,小偃6号籽粒产量高于西农979,高肥力条件下则相反。小麦百公斤籽粒需氮量随品种演替有降低的趋势,但随土壤肥力水平提高有增加的趋势。土壤肥力与品种对百公斤籽粒需氮量也有显著的交互作用。在小麦品种更替过程中氮肥生理效率和农学效率均呈增加的趋势,但随着土壤肥力水平的提高,各品种小麦的氮肥生理效率呈下降的趋势,氮肥农学效率呈先升高后下降的抛物线变化趋势。土壤肥力与品种对小麦氮肥生理效率和农学效率无明显交互作用。【结论】陕西关中小麦品种演替在高肥力以及养分投入充足时不仅表现出单产不断提高,而且氮效率也呈逐步增加的趋势。因此,品种更新的同时还要注重提升土壤肥力,才能保证粮食安全,实现农业生产可持续发展。

Responses of Grain Yield and Nitrogen Use Efficiency of Wheat Cultivars Released in Different Decades to Soil Fertility in Shaanxi Guanzhong Plain

【Objective】 With the aim of investigating the responses of grain yield and nitrogen efficiencies of winter wheat cultivars released in different decades to various levels of soil fertility status in Shaanxi Guanzhong Plain. 【Method】 The performance of three representative leading wheat cultivars released from 1980s to 2010s under a gradient of soil fertility levels, which had been receiving diverse fertilization treatments for 33 years was evaluated. The winter wheat cultivars are cultivar Xiaoyan 6 in 1980s, cultivar Xiaoyan 22 at the end of 1990s and cultivar Xinong 979 after 2005. The fertilization treatments including different quantities and/or types of mineral fertilizers and organic manure, they are control (CK, no nutrient input), combination of two rates of nitrogen and phosphorus fertilizers (N1P1, N2P2) and their combination with two doses of organic manure (M1N1P1, M1N2P2, M2N1P1, M2N2P2). 【Result】 The results showed that the grain yield and harvest index of wheat showed an increasing trend with cultivar evolution under same soil fertility level, particularly under higher fertility soils. The grain yield of wheat increased with the improving soil fertility and the amount of fertilizers supplied, with the highest yield increase observed for cultivar Xinong 979 ranged from 151.0% to 610.5%, the least for cultivar Xiaoyan 6 at a range of 148.1%-341.8%, and the cultivar Xiaoyan 22 in between ranged from 127.9% to 349.7%. The soil fertility and cultivar showed a significant interaction effect on grain yield and harvest index of wheat, under lower soil fertility, the grain yield of cultivar Xiaoyan 6 was higher than that of cultivar Xinong 979, and vice versa under high fertility. The nitrogen requirement for producing 100 kg wheat grain showed a decreasing trend with cultivar evolution, but it tended to increase with the increasing soil fertility and the quantity of fertilizers supplied for individual variety. And a considerable interaction effect of soil fertility and cultivar was also observed on the nitrogen requirement for producing 100 kg wheat grain. Both nitrogen physiological efficiency and nitrogen agronomic efficiency showed the increasing trends with cultivar evolution. But the former tended to be declined with improving soil fertility while the latter exhibited the features of a parabolic curve with increasing amount of fertilizer/manure applied. There is no interaction effect of soil fertility and cultivar on nitrogen physiological efficiency and nitrogen agronomic efficiency of winter wheat. 【Conclusion】 The updated wheat varieties could achieve improvingly higher grain yield potential and increased nitrogen efficiencies only under high fertility soil conditions where the nutrients are sufficiently supplied in Shaanxi Guanzhong Plain. Therefore, cultivation of new varieties should be synchronized with the improving soil fertility to assure food security and reach a sustainable agricultural production.