秸秆还田条件下氮肥对水稻幼苗生长及养分吸收的影响  

Effect of nitrogen on rice seedling growth and nutrient uptake under wheat straw returning

作　　者：杜康[1] 谢源泉 林赵淼[1] 刘正辉[1,2] 王绍华[1] 丁艳锋[1,2] 

机构地区：[1]南京农业大学农学院,江苏南京210095 [2]江苏省现代作物生产协同创新中心,江苏南京210095

出　　处：《南京农业大学学报》2016年第1期18-25,共8页Journal of Nanjing Agricultural University

基　　金：国家自然科学基金项目(31171485;31470086);国家863计划项目(2014AA10A605);"十二五"国家科技支撑计划项目(2012BAD04B08;2013BAD07B09)

摘　　要：[目的]水稻僵苗是当前小麦秸秆还田中亟待解决的重要问题。本研究拟通过分析秸秆还田条件下氮肥对水稻幼苗生长及养分吸收的影响,明确水稻僵苗的可能机制及应对措施。[方法]以粳稻品种‘宁粳3号’为材料,采用盆栽方式分别在秸秆还田和秸秆不还田下设置5种氮肥处理。测定不同处理水稻幼苗的分蘖、株高、干物质积累、根系活力以及营养元素含量。[结果]与对照(秸秆不还田)相比,秸秆还田下茎蘖数、株高、地上部干物质积累以及氮、磷和钾含量均显著下降。根系活力、地下部干物质积累以及氮、磷和钾含量分别比对照降低26.6%、8.1%、13.2%、20.8%和15.4%。秸秆还田条件下,增加施氮量促进水稻幼苗生长、干物质积累以及矿质营养元素的吸收;与无氮肥处理相比,施用氮肥处理水稻幼苗地下部干物质积累、根系活力、地下部氮、磷和钾含量分别增加86.1%、45.0%、29.7%、32.4%和67.8%;高氮下,增加分蘖肥比例提高水稻幼苗根系活力,增加水稻幼苗茎蘖数和干物质积累。[结论]秸秆还田导致水稻僵苗的原因可能是根系生长量低、活力差而导致的养分吸收能力不足;适度增施氮肥,尤其是增加分蘖肥比例,有助于提高秧苗活力,改善秧苗生长。[Objectives]Growth of rice seedlings is vulnerable to being stunted by short-term straw returning. In order to explore the underlying mechanisms of stunted seedlings and its remedial measures,effect of nitrogen on growth and nutrients uptake of rice seedlings under wheat straw returning was determined in the present study. [Methods]Using a japonica rice cultivar‘Ningjing 3 ＇,the pot experiment was conducted with 5 nitrogen treatments. Tiller number,plant height,dry matter accumulation,root activity and mineral concentration of rice seedling were measured. [Results]Incorporation of wheat straw negatively affected tiller number,plant height,dry weight,N,P and K concentrations in shoot of rice seedlings. Compared with non-straw returning,root dry weight,root activity,and N,P and K concentrations decreased by 8. 1%,26. 6%,13. 2%,20. 8%,and 15. 4%,respectively. N fertilizer promoted plant growth,dry weight and mineral nutrients uptake. Compared with non-N fertilizer,N application increased root dry weight,root activity,N,P,and K concentrations of rice seedlings by 86. 1%,45. 0%,29. 7%,32. 4%,and 67. 8%,respectively. Increasing the ratio of tillering fertilizer improved root activity,tiller number and dry matter accumulation at high N level treatment. [Conclusions]Weak function of root was the cause of worse performance of rice seedlings under wheat straw returning,which can be alleviated by increasing basal N fertilizer at tillering stage,especially increasing the ratio of tillering fertilizer.

关 键 词：水稻 秸秆还田 氮肥 根系活力 营养吸收 

分 类 号：S511[农业科学—作物学] S311