摘要
【目的】研究陕西关中冬小麦/夏玉米区土壤磷素分布特征及近30年农田土壤有效磷变化,对维持和提高土壤质量和土地生产力,合理施磷和减磷增效具有重要意义。【方法】利用2011年在陕西关中平原冬小麦/夏玉米种植区选择的10个典型县、区采集的458个土壤样本,通过与1980年土壤普查土壤有效磷含量数据的比对,分析近30年来陕西关中农田耕层土壤有效磷的变化及当前土壤磷库分布特征。【结果】30年来该区农田耕层土壤有效磷含量整体呈显著上升,宝鸡市、咸阳市和渭南市的平均有效磷含量分别为26.09、27.50和21.53 mg·kg-1,与第二次土壤普查有效磷含量结果相比,增幅分别达334.83%、276.71%和231.23%。高有效磷等级地块的比例均有大幅度增加,其中以有效磷含量15—30 mg·kg-1的增幅最大,有效磷含量<10 mg·kg-1的降幅最大。有效磷和无机磷总量分布呈现出西部(宝鸡市)和中部(咸阳市)高于东部(渭南市),而有机磷含量则相反。当前关中地区大面积土壤有效磷含量高于农学阈值,可满足作物高产时的磷素供应。同时,宝鸡、咸阳市土壤有效磷含量>37 mg·kg-1的累积分布概率超过20%,水溶性磷含量>2 mg·kg-1的累积分布概率超过22%,存在较高的水环境污染风险。【结论】长期集约化高强度种植条件下含磷肥料的过量施用显著提高了土壤有效磷含量。从保护环境和合理利用有限的磷资源角度考虑,应合理调控磷肥施用,做到因土施肥,因需供肥。
【Objective】It is of great significance to maintain and improve soil quality and land productivity,meanwhile enhance the phosphorus(P)use efficiency by studying the distribution characteristics and changes of soil phosphorus in winter wheat/summer maize cropping in Shaanxi Guanzhong Plain in recent 30 years.【Method】Based on 458 soil samples collected in total in 2011 from 10 typical counties in winter wheat/summer maize cropping in Guanzhong Plain analysis data,we compared its Olsen P content with the soil survey data in 1980s,and also explored the distribution characteristics of the current soil phosphorus pools at the regional level.【Result】The results showed that the soil Olsen P content in the plough layer soils significantly increased during the past 30 years.The mean values of soil Olsen P in Baoji,Xianyang and Weinan were 26.09 mg·kg-1,27.50 mg·kg-1 and 21.53 mg·kg-1,respectively,compared with soil survey data in 1980s,the corresponding increasing rate were 334.83%,276.71%and 231.23%,respectively.The proportions of cultivated land with higher soil Olsen P levels were significantly increased,with the largest increase was observed in 15-30 mg·kg-1 and the largest decrease in Olsen P<10 mg·kg-1.The total distribution of soil Olsen P and inorganic phosphorus was higher in the west(Baoji City)and the middle(Xianyang City)than in the east(Weinan City),and organic phosphorus content was opposite.At present,the soil Olsen P level in the large area of Guanzhong Plain under winter wheat/summer maize cropping was higher than the agronomic threshold,which could meet the supply of phosphorus in high yield crops.Meanwhile,the cumulative distribution probability of soil Olsen P content(greater than 37 mg·kg-1)was more than 20%in Baoji and Xianyang,the cumulative distribution probability of water-soluble P content(greater than 2 mg·kg-1)was more than 22%,so there would be a higher risk of water environment pollution.【Conclusion】Excessive application of phosphorus fertilizer under long-term intensive and high-intensity planting conditions significantly increased the Olsen P content in soil.Considering the protection of environment and rational utilization of limited phosphorus resources,the application of phosphorus fertilizer should be regulated reasonably,so as to apply fertilizer according to soil and supply fertilizer according to demand.
作者
刘琳
吉冰洁
李若楠
BATBAYAR Javkhlan
张树兰
杨学云
LIU Lin;JI BingJie;LI RuoNan;BATBAYAR Javkhlan;ZHANG ShuLan;YANG XueYun(College of Natural Resources and Environment,Northwest A&F University/Key Laboratory of Plant Nutrition and the Agro-environment in Northwest China,Ministry of Agriculture and Rural Affairs,Yangling 712100,Shaanxi)
出处
《中国农业科学》
CAS
CSCD
北大核心
2019年第21期3878-3889,共12页
Scientia Agricultura Sinica
基金
国家重点研发计划项目(2017YFD0200205)
