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以设置在沈阳潮棕壤上的连续12年的田间定位磷微区试验为依托,研究在不同磷肥施用条件下(施用量和施磷频次),玉米产量、养分吸收以及土壤养分平衡状况。结果表明:磷素不是该研究区域玉米生产的主要限制因子;施肥促进养分吸收,其各处理间增加趋势为氮磷>氮>对照,并且一次性施磷肥方式优于每年施磷肥方式;与土壤本底值相比,施肥后土壤耕层(0~20 cm)全磷、速效磷、全氮、碱解氮呈增加趋势,由于长年没有外源钾的补充,土壤全钾和速效钾呈下降趋势,其各处理间下降趋势为氮磷>氮>对照;土壤速效磷在不施用肥料条件下有下降趋势,只施用氮肥条件下有增加趋势,只是两者变化并不很明显;在每年施磷条件下,土壤速效磷量呈缓慢上升趋势,而在一次性施磷条件下,施肥当年的土壤速效磷量激增,而后呈减小的趋势,即与每年施磷肥方式相比,一次性施磷方式更有利于建立土壤“宏大”有效磷库;为了保证土壤养分平衡,在施用足量氮肥的前提下,施用磷肥量为等于或略高于作物移出磷量,施氮磷比控制在1∶0.167到1∶0.5之间。
Based on the 12-year field experiment of P micro-location set on tidal brown soil in Shenyang, the yield and nutrient uptake of maize and soil nutrient balance were studied under different P application conditions. The results showed that: P was not the main limiting factor for maize production in the study area. Fertilization promoted nutrient uptake, and the increasing trend among the treatments was N> P> N> Compared with the background value, the contents of total phosphorus, available phosphorus, total nitrogen and available nitrogen in soil topsoil (0 ~ 20 cm) increased after fertilization. Due to the lack of exogenous potassium supplementation for many years, total potassium and available potassium in soil The trend of decline in each treatment was nitrogen and phosphorus> nitrogen> control. Soil available phosphorus had a decreasing trend under the condition of no fertilizer application, but increased under the condition of applying nitrogen fertilizer only, but the change of the two was not obvious. Under the condition of applying phosphorus, the content of available phosphorus in soil showed a slowly rising trend. Under the condition of one-time phosphorus application, the available phosphorus in soil increased rapidly in the year of applying fertilizers, and then decreased. That is to say, In order to ensure the balance of soil nutrients, under the premise of enough nitrogen fertilizer application, the application of phosphorus fertilizer is equal to or slightly higher than that of crops to remove phosphorus, and the N / P ratio Control at 1:0.167 to 1:0.5 .