【作者】 陈惠哲；

【导师】 朱德峰；

【作者基本信息】 中国农业科学院 ， 作物栽培与耕作学， 2013， 博士

【摘要】 随着社会经济发展，农村劳动力转移和老龄化，机械化种植是我国现代稻作技术的发展方向。传统机插秧耕作整地存在过度旋耕，稻田耕作层深，田间机插作业易陷入泥浆中，及秧苗机插较深，影响秧苗返青、分蘖发生和产量。水稻免耕机插技术发展有助于解决免耕直播和免耕抛秧存在问题，完善我国现有免耕栽培技术体系。本研究以翻耕机插为对照，通过比较水稻免耕机插质量、生长特性、产量形成和经济效益。在免耕条件下开展土壤泡田、机插密度和氮肥施用量等关键栽培措施研究，为完善水稻免耕机插栽培提供技术支持。研究结果如下：1、明确了水稻免耕的机插质量、生长及产量形成特性。传统土壤翻耕机插后秧苗种植过深，不利分蘖发生及秧苗生长。免耕机插有利于改善秧苗机插深度，可实现秧苗浅插，秧苗种植深度比对照可浅栽40%以上；且有利于插秧机田间作业，但翻秧率、漂秧率和伤秧率均比翻耕对照上升；免耕机插促进水稻分蘖发生，增加单株穗数，但抑制根系生长，总根量下降，且根系多集中于表层(0-5cm)；抽穗后水稻功能叶叶绿素较高；2年试验比较，免耕机插产量比翻耕略有增产，在0.6%-2.3%范围，与对照差异不显著，不同品种及年度间增产幅度存在差异；分析产量构成表明免耕机插主要增加了单位面积有效穗数。2、明确了泡田对免耕土壤容重及水稻机插质量影响。随着泡田时间延长，土壤容重下降，免耕机插稻田泡田15d后，0-25cm表层的土壤容重可下降到0.8-0.9g/cm~3，此时可达到较好的机插效果，秧苗机插深度较为理想，在1.0-1.9cm，且漂秧率、翻秧率、伤秧率与传统机插对照无显著差异；提出免耕机插稻田需泡田10天以上；泡田时间不足，土壤没有充分软化，秧苗会机插过浅，造成大量漂秧，影响机插效果及产量。3、确定了水稻免耕机插合理种植密度。水稻免耕机插在行距30cm固定，株距16-21cm范围内可通过缩小株距，增加机插密度来提高产量；种植密度增加，有利于增加高峰苗和有效穗数，提高成穗率和群体叶面积指数，基部透光率下降，提高光能利用，促进高产群体形成和后期干物质积累，并有利于水稻叶片吸氮量、茎鞘吸氮量和群体总吸氮量的增加。4、明确了水稻免耕机插的氮肥用量及利用率。免耕机插的施氮量与产量呈单峰曲线，施氮量增加产量呈现先增后减趋势，有效穗增加但成穗率下降；种植密度下降需增加施氮量才能获得高产；增施氮素促进叶片变长和提高叶绿素含量，氮农学利用率和氮肥偏生产力随施氮量增加而下降，适宜施氮有利于氮素的吸收积累，杂交稻免耕机插合理种植密度在21.0丛/m2左右，合理的氮肥用量在180kg/hm2左右。5、评价了水稻免耕机插的经济效益，提出技术发展对策。免耕机插比翻耕机插平均产量增产1.25%，不同品种间有差异，实现平均增产增收276元/hm2；免耕机插除草成本大幅上升，主要系除草剂及人工除草费用增加，由于不需要机械耕地，机械作业成本大幅下降，综合增产增收和支出，水稻免耕机插的经济效益比传统机插略高。需要进一步完善土壤管理、养分管理、杂草防冶等关键栽培措施，促进水稻免耕机插技术发展。更多还原

【Abstract】 The quantity and quality of labor for rice production declined markedly, mechanized planting willbecame more and more important in rice production system in China. Conventional tillage is the mostwidely used method for land preparation of paddy field, and transplanting is the traditional but stilldominant method for rice establishment. There are some disadvantages in conventional tillage systemcompare with no tillage, such as that cultivation layer is much deep for mechanized planting due toexcess tillage, the plant depth is too deep in field with conventional tillage, that is disadvantage togrowth recovery, tiller and yield formation. In this study, we compared mechanized transplanting quality,biomass production, yield components and economic benefits between no tillage and conventionaltillage. We study the effects of soil soak time, planting density and nitrogen rates on rice growth underno tillage condition. The results are as follows:1. It is clear that the effect of no tillage on transplanting quality, seedling growth and yield. The plantdepth is too deep in field with conventional tillage that is disadvantage to tiller and seedling growth.The seedling plant depth reduced40%under no tillage conditions compared with conventionaltillage conditions. The percentage of floating seedling and damage seedling was much higher underno tillage conditions than conventional tillage conditions. The tiller and panicles per plant increased,but root biomass and length decreased under no tillage conditions compared with conventionaltillage conditions, and no tillage caused root accumulation in surface soil layer (0-5cm). Thechlorophyll concentration of flag leaf was higher under no tillage conditions than conventionaltillage conditions after flowering. The yield under no tillage conditions was higher than underconventional tillage (0.6%-2.3%), but it is not significant. The increase percentage of yield wasdifferent in different year and varieties.2. The effects of soil soak duration on soil bulk density and mechanized transplanting quality wasclear. The soil bulk density decreased with soil soak duration increased, the soil bulk densitydecreased to0.8-0.9g/cm~3in0-25cm depth after15days soil soak duration, the transplanting depthwas in1.0-1.9cm, and the percentage of floating seedling, lodging seedling and damage seedingwas not significant difference compare with traditional mechanized transplanting. In view of theeffects of soil soak duration on soil bulk density, mechanized transplanting quality and yield, it isgood for mechanized transplanting that the field soil soak duration required more than10days. Ifsoil soak time was not enough, bulk density was high for mechanized transplanting in the surfacesoil layer, resulting in a large number of floating seedlings.3. The fitting density for mechanized transplanting under no-tillage condition was found. The rowspace was not changed, but the hill space can be changed in16-21cm, the rice yield improved whenthe hill space reduced and planting density increased. The higher planting density resulted inincreasing the max tiller number, panicle number, and leaf area index, reducing light transmittance,improving solar utilization, total biomass and nitrogen uptake.4. It is clear that the effect of nitrogen rate on rice growth and nitrogen use efficiency under no-tillage mechanized transplanting system. It is a single peak curve relation between nitrogen rate and yield.The panicle number increased with nitrogen rate, but the effective panicle percentage decreased.The high yield can obtain through enhancing nitrogen input under low planting density condition.The leaf length and chlorophyll content increase when nitrogen input increase, nitrogen agronomicefficiency and the nitrogen partial factor productivity decreased with the nitrogen rate increased, theoptimum planting density was21hills per m2, and the optimum nitrogen input was180kg/hm2.5. The economic benefit of no tillage mechanized transplanting system was determined, and establishthe method to support the no-tillage mechanized transplanting system.The average yield was1.25%higher under no tillage than conventional tillage condition. There were differences between thedifferent varieties, the average increase of income was276yuan/ha. Weeding costs increasedsharply under no-tillage mechanized transplanting system due to increase of herbicides and manualweeding costs. Economic benefit was much higher under no tillage system than conventional tillagesystem. Further research need to be conduct such as soil management, nutrient management andweed control to improve no-tillage mechanized transplanting system.更多还原