不同种植方式对稻茬紫云英的生长及土壤养分的影响

研究绿肥作物种植方式对其生长状况及土壤特性的影响，可为长江下游农区“水稻(Oryza sativa L.)—绿肥作物”轮作模式下如何以草增粮提供科学依据。于2018~2019年在江苏省昆山市采用套播留茬、浅旋直播、板茬直播3种种植方式，研究不同绿肥种植方式对自身群体基础、越冬稳定性、生育进程、主要形态指标、产草量及还田后土壤养分动态的影响。结果表明，相同播种量水平下，浅旋直播的群体起点最高，为58.29万基本苗/hm ²；越冬稳定性以套播留茬方式最高，越冬率为94.3%。不同种植方式下生育进程递进规律总体一致，主要影响绿肥作物的营养生长期，套播留茬方式的营养生长期最长（122 d），比最短的浅旋直播方式高出20 d。套播留茬方式下的株高、茎粗及其他主要形态指标明显高出其他两种方式。套播留茬方式的鲜草产量最高，浅旋直播方式居中，板茬直播方式最低，且均超过30 000 kg·hm^-2。翻压还田后，3种方式下土壤有机质、全氮、铵态氮、硝态氮、速效磷、速效钾等土壤养分含量均有一定的增加，其中套播留茬方式增加幅度最高。

Effects of Different Planting Methods on the Growthand Soil Nutrients of Chinese Milk Vetch

The research of effects of green manure crops planting methods on their growth status and soil characteristics can provide a scientific basis for increasing food production through planting green manure grass in rice-grass rotation mode in the lower reaches of the Yangtze River. The experiment on the effects of different green manure planting methods such as interplanting with stubble, direct seeding by shallow rotary tillage, direct seeding and no-tillage on the population basis, overwintering stability, growth process, main morphological indexes, grass production and soil nutrient dynamics after returning to the field were carried out in Kunshan City of Jiangsu Province from 2018 to 2019. It showed that the basic seedling number was highest under interplanting with stubble, with 582 900 basic seedlings per hectare, meanwhile, with the highest over-wintering rate (94.3%) among the three planting methods mentioned above when the sowing quantity was same.The growth processes of the green manure crops were basically same among the three planting methods, and the evidential difference may be found at the vegetative growth stage, which was longest for 122 days under interplanting with stubble. However, the vegetative growth state under direct seeding by shallow rotary tillage was shortest, only lasted for 102 days. The plant height, stem diameter and other main morphological indexes under interplanting with stubble were significantly higher than the other two planting methods. The fresh yield of green manure crops under the three methods all were above the level of 30,000 kg·hm ^-2, of which, interplanting with stubble was maximum, direct seeding by shallow rotary tillage was middle, and direct seeding and no-tillage was minimum. The content of soil organic matter, total nitrogen, ammonium nitrogen, nitrate nitrogen, available phosphorus, available potassium and other soil nutrients under the three planting methods all increased when applying green manure to soil, by the maximum proportion under interplanting with stubble.