施磷对麦/玉/豆套作体系土壤磷素变化的影响  

Effects of phosphorus application on changes in soil phosphorus under wheat/maize/soybean strip relay intercropping system

作　　者：周涛[1] 徐开未[1] 黄蔚[1] 陈新平[2] 张朝春[2] 刘静[1] 卢俊宇 陈远学[1] 

机构地区：[1]四川农业大学资源学院,成都611130 [2]中国农业大学资源与环境学院,北京100193 [3]雅安市农业局,雅安625014

出　　处：《中国生态农业学报》2015年第7期823-831,共9页Chinese Journal of Eco-Agriculture

基　　金：国家玉米产业技术体系项目(CARS-02-24);国家自然科学基金重大国际(地区)合作项目(31210103906)资助

摘　　要：小麦/玉米/大豆带状套作是四川省丘陵低山区主要旱地作物生产体系,了解该体系磷养分变化对优化磷肥管理和促进可持续生产有重要意义。本研究通过连续3年（2011—2013年）田间定位试验,设置P0、P1、P2、P3和P4共5个磷（P2O5）水平（玉米带分别为0 kg·hm^-2、37.5 kg·hm^-2、75 kg·hm^-2、112.5 kg·hm^-2、150 kg·hm^-2,小麦-大豆带分别为0 kg·hm^-2、45 kg·hm^-2、90 kg·hm^-2、135 kg·hm^-2、180 kg·hm^-2）,探讨该体系中土壤全磷、速效磷、水溶性磷的变化规律和速效磷的年际变化。结果表明：在麦/玉/豆套作体系中施磷165 kg（P2O5）·hm^-2（玉米带75 kg·hm^-2,小麦-大豆带90 kg·hm^-2）,可以满足体系作物对磷的需求,基本达到磷的表观平衡,维持土壤速效磷含量在20 mg·kg^-1左右。3年后5个磷水平下体系耕层土壤（0~20 cm）全磷变化量分别为-0.024 g·kg^-1·a-1、-0.016 g·kg^-1·a-1、0.016 g·kg^-1·a-1、0.11 g·kg^-1·a-1、0.15 g·kg^-1·a-1,速效磷变化量依次为-1.2 mg·kg^-1·a^-1、-0.9 mg·kg^-1·a^-1、0.2 mg·kg^-1·a^-1、2.0 mg·kg^-1·a^-1和2.7 mg·kg^-1·a^-1。通过线性平台函数的模拟,该体系中玉米、小麦、大豆产量的土壤速效磷临界值分别为16.5 mg·kg^-1、12.6 mg·kg^-1和8.8 mg·kg^-1。当土壤全磷含量低于0.55 g·kg^-1时,土壤全磷每增加0.1 g·kg^-1,土壤速效磷增加1.70 mg·kg^-1;当土壤全磷大于0.55 g·kg^-1,全磷每增加0.1 g·kg^-1,土壤速效磷增加6.49 mg·kg^-1。当土壤速效磷含量在40 mg·kg^-1以下时,速效磷每增加1 mg·kg^-1,水溶性磷增加0.017 mg·kg^-1。综上,在麦/玉/豆体系磷肥管理中应该维持土壤全磷含量低于0.55 g·kg^-1,同时速效磷含量在20 mg·kg^-1左右,这样既可以保证作物产量和系统生产力又不会产生较大的环境威胁。In Southwest China, one of the most densely populated agricultural regions, intercropping has been practiced in major grain production systems for a long period. Wheat/maize/soybean strip relay intercropping（W/M/S） system is one of the main planting patterns in Sichuan Province. In the system, wheat was sowed in autumn of the last year, maize transplanted around half month before wheat harvest, and soybean sowed after wheat harvest. This system is very important for achieving optimal crop yield, promoting system productivity and simultaneously decreasing phosphorus（P） losses through optimizing soil P management in the system. A three-year field experiment（2011-2013） was conducted with 5 P application rates [on maize strip： 0 kg·hm^-2, 37.5 kg（P2O5）·hm^-2, 75 kg（P2O5）hm^-2, 112.5 kg（P2O5）·hm^-2 and 150 kg（P2O5）·hm^-2; on wheat strip： 0 kg（P2O5）·hm^-2, 45 kg（P2O5）·hm^-2, 90 kg（P2O5）·hm^-2, 135 kg（P2O5）·hm^-2 and 180 kg（P2O5）·hm^-2; soybean was not fertilized] to determine the changes in soil Olsen-P, total P, Ca Cl2-P and annual variability of available P in the cropping system. The results showed that P application rate at 165 kg（P2O5）·hm^-2（75 kg·hm^-2 on maize strip and 90 kg·hm^-2 on wheat-soybean strip, P2 treatment） met the demand for P in W/M/S system. There was an apparent balance between P input and P output with soil Olsen-P content maintained at 20 mg·kg^-1 The linear-plateau model well described the correlation between Olsen-P and crop yield, with the change-point showing that the critical levels of soil Olsen-P for maximum wheat, maize and soybean yields were 12.6 mg·kg^-1 16.5 mg·kg^-1and 8.8 mg·kg^-1 respectively. From 2011 to 2013, soil Olsen-P in the top 0-20 cm soil layer under P0, P1, P2, P3 and P4 treatments（P application rates of the W/M/S system were the total of wheat and maize application rates, respectively） changed by -1.2 mg·kg^-1a-1, -0.9 mg·kg^-1a-1, 0.2 mg·kg^-1a^-1, 2.0 mg·kg^-1a^-1 and 2.7 mg·kg^-1a^

关 键 词：磷肥 小麦/玉米/大豆带状套作 速效磷 水溶性磷 临界值 

分 类 号：S158.3[农业科学—土壤学] S158.5[农业科学—农业基础科学]