小麦玉米轮作体系氮、磷吸收与平衡研究

Study on Absorption and Balance of Nitrogen,Phosphorus in Winter Wheat and Summer Maize Rotation System

当前在作物生产中氮磷资源的不合理利用严重威胁环境，为了探讨华北山前平原冬小麦-夏玉米轮作体系合理的氮磷配合措施，在几年水氮（水磷）定位试验基础上对氮磷吸收与利用状况进行了分析。试验为小麦-玉米周年轮作种植，设水氮和水磷试验，水分为主区，施氮（磷）量为副区，裂区试验设计。水分设置限水和适水2个处理，周年设置6个施氮水平，小麦＋玉米氮肥用量分别为0＋0，60＋60，120＋120，180＋180，240＋240，300＋300 kg ／hm2；3个施磷水平，小麦季磷肥用量分别为75，150，225 kg ／hm2，玉米季不施磷。结果表明，施氮（磷）可提高作物地上部分吸氮（磷）量，小麦和玉米全年施氮量240 kg ／hm2即可达到较高的地上部总吸氮量，限水和适水下施氮量分别为218．7，243．5 kg ／hm2才能保证氮素盈余量为零。小麦和玉米全年施磷量75～150 kg ／hm2可达到较高的地上部总吸磷量，但限水和适水下施磷量分别为49．4，69．9 kg ／hm2才能保证磷素盈余量为零。冬小麦对氮和磷的生产效率低于夏玉米，限水和适水下百千克籽粒吸氮量小麦分别为2．4，2．3 kg，平均为夏玉米的1．42倍；百千克籽粒吸磷量小麦均为0．61 kg，平均为夏玉米的1．23倍。当限水和适水下土壤全氮含量分别达0．102％和0．097％、全磷含量分别达0．213％和0．209％时土壤即可保持养分盈余量为零。土壤水分含量较高使植株对氮磷的吸收量也较高，但百千克籽粒吸氮（磷）量却表现出相反的趋势。在华北山前平原区小麦玉米轮作体系周年施氮量218．7～243．5 kg ／hm2、施磷量49．4～69．9 kg ／hm2可实现氮磷盈余量为零。

In the current,application of nitrogen （N）and phosphorus （P）fertilizer is unreasonable in crop production,which serious threat to the environment,in order to explore a reasonable measures in applying N and P for the winter wheat and summer maize rotation system in North China Plain,and absorption and utilization status of N and P was analyzed basing on a few years foundation location test of water and nitrogen （phosphorus）.In the win-ter wheat and summer maize rotation system,the split plot design was employed with main plot of water （limiting water and suitable water）,sub-plot of nitrogen fertilizer 0 ＋0,60 ＋60,1 20 ＋1 20,1 80 ＋1 80,240 ＋240 and 300 ＋300 kg /ha respectively,for wheat and maize rotation system,and sub-plot of phosphorus fertilizer 75,1 50,225 kg /ha respectively for wheat,and three replicates in each sup-plot.The main results showed that N and P absorbing a-mount in shoot could be increased relying on application of N and P fertilizer,but it could not continue to bring high absorption when excessive application of N and P fertilizer.When annual N application amount reached 240 kg /ha, the higher N in shoot could be achieved,and N application amount reached to 21 8.7,243.5 kg /ha,which could en-sure the nitrogen surplus was zero.When annual P application amount reached 75 -1 50 kg /ha,the demand for P of wheat and maize would be met,but P application amount reached to 49.4,69.9 kg /ha,which could ensure the P＆amp;nbsp;surplus was zero.Compared with summer maize,the demand of nitrogen and phosphorus was higher for winter wheat,and which was 1 .42,1 .23 times respectively.1 00 kg grain nutrient uptake of wheat were 2.4,2.3 kg for N, and 0.61 kg for P under limiting water and suitable under water.When total nitrogen content were up to 0.1 02%and 0.097% respectively,and the total phosphorus content were 0.21 3% and 0.209% respectively under the con-dition of limited water and suitable water,and the overmeasure of N and P was zero.N and P in shoot were higher when soil moisture content was higher,but absorptive N and P amount per hundred kilograms grain that showed the opposite trend,it explained that better moisture condition can promote the absorption of N and P in plant,but the rate of nutrient uptake rate which was less than the yield increase.For winter wheat and summer maize rotation sys-tem,N and P balance would be achieved when N application rates was 21 8.7 -243.5 kg /ha,and P application rates was above 49.4 -69.9 kg /ha,respectively.