暗管排水对规模农田水稻养分吸收和产量构成的影响

为探究暗管排水对水稻生育后期植株氮、磷、钾养分吸收以及产量构成的影响,以‘南粳46’为试验材料,通过苏州太仓东林农场两块相临的暗管排水田块与传统明沟排水田块进行试验。在暗管排水田距离排水沟和暗管不同的位置采集水稻样品,未铺设暗管的田块取样作对照,分析孕穗期、抽穗期和成熟期水稻植株氮磷钾含量以及产量构成之间的差异。结果表明：随苗沟距的增加,水稻植株氮磷钾养分吸收有减小趋势,靠排水沟越近的区域影响最显著。苗管距2.5 m处植株各器官氮磷钾含量以及产量最高,水稻各器官氮、磷、钾吸收量相对于对照组最高分别可提高25.17%、80.16%和35.19%;产量在苗沟距15 m、苗管距2.5 m处理下达到9.97 t/hm²,大于对照组15.22%,产量差异主要由水稻群体的穗粒数、结实率和千粒重产生。暗管排水可以有效增加稻田氮磷钾养分的吸收和稻田局部增产,但自由暗管排水可能导致暗管正上方表层土壤养分流失而影响水稻植株氮磷钾养分吸收,对于氮磷钾养分吸收规律需后期结合土壤渗漏强度以及渗漏量与土壤养分含量的关系做进一步分析。

Effect of Pipe Drainage on Scale Farmland Rice Nutrient Absorption and Yield Composition

To explore the effect of underground pipe drainage on the absorption of nitrogen, phosphorus and potassium and yield components of rice plants at later stages of growth, ‘Nanjing 46’ was used as the test material, an experiment was conducted in two adjacent field blocks of underground pipe drainage and traditional open ditch drainage in Taicang Donglin Farm of Suzhou City. Rice samples were collected at different locations from the ditch (seedling ditch spacing) and different locations from the pipe (seedling pipe spacing) in the underground pipe drainage field block and the sampling of the traditional open ditch drainage field block was used as a control, to analyze the difference of the nitrogen, phosphorus and potassium content and the yield composition of the rice plants at the jointing booting stage, long earing stage and mature stage. The results showed that: with the increase of the seedling ditch spacing, the absorption of nitrogen, phosphorus and potassium of rice plants had a tendency to decrease, and the area closer to the drainage ditch had the most significant effect. The nitrogen, phosphorus and potassium content and yield of each organ of the rice plant at the seedling pipe spacing of 2.5 m were the highest. Compared with the control group, the absorption of nitrogen, phosphorus and potassium in different organs of rice could have a maximum increase by 25.17%, 80.16%, and 35.19%, respectively. The yield reached 9.97 t/hm² when the seedling ditch spacing was 15 m and the seedling pipe spacing was 2.5 m, which was 15.22% greater than the control group. The difference in yield was mainly caused by the number of grains per spike, seed setting rate and thousand-grain weight of the rice population. Underground pipe drainage could effectively increase the absorption of nitrogen, phosphorus and potassium in paddy field and increase part yield, but free underground pipe drainage might cause the loss of surface soil nutrients directly above the underground pipes and affect the absorption of nitrogen, phosphorus and potassium in rice plants, and the law of nitrogen, phosphorus and potassium absorption should be further analyzed in the later stage in combination with the relationship between soil leakage intensity or leakage amount and soil nutrient content.