【作者】 吉艳芝；

【导师】 刘树庆； 张丽娟； 巨晓棠；

【作者基本信息】 河北农业大学 ， 土壤学， 2010， 博士

【摘要】 本研究采用甜玉米（Zea mays L.）、苋菜（Amaranthus spp.）和甜高粱（Sorghum Linn.）作为填闲作物,研究不同填闲作物种类及其根层调控措施进行田间原位修复试验,以消减土壤剖面根层NO₃-N累积和降低土壤剖面NO₃-N淋失为目标,分析不同填闲作物种类及根层调控措施对NO₃-N淋洗的影响,明确填闲作物对下季作物产量和土壤NO₃-N的影响,主要结果如下:（1）甜玉米的生物量和吸氮量最大,对土壤剖面NO₃-N的消减效果最好,2008年和2009年消减NO₃-N分别为153.76和605.70kg/hm2。从NO₃-N的表观平衡看,两季填闲的0-200cm土体NO₃-N的损失均以休闲最高;三种填闲作物比较,2008年甜玉米的N素损失量最低,2009年苋菜的最低,但与甜玉米无显著差异（P<0.05）。说明填闲作物的种植能够降低设施蔬菜土壤剖面NO₃-N的累积,其中以甜玉米的效果最佳。（2）在生物量和吸氮量上,调理剂和秸秆还田的处理无显著差异（P<0.05）,但均高于传统种植处理。两季填闲收获后的休闲处理的土壤剖面NO₃-N累积量最高,填闲种植的NO₃-N累积峰均在90-100cm,而休闲则在120-140cm。在土壤剖面NO3-N含量的动态变化中,休闲始终处于高残留状态。三种根层调控措施对土壤NO₃-N的含量影响,均在甜玉米的大喇叭口期（种植后40天）出现NO₃-N的减低,一直持续到收获,但秸秆还田在种植60天时出现一个高累积峰,从影响的土层深度上可以看出,传统种植影响到60cm,调理剂和秸秆还田则到了80cm。（3）两年的水分渗漏量和NO₃-N淋失量趋势一致;2008年水分渗漏量高于2009年,这与2008年的降雨量大有关系。①不同填闲作物种类比较,2008年休闲、甜玉米、苋菜和甜高粱NO₃-N淋失量分别为3.6,1.9,2.4和2.6 kg/hm2,分别比休闲减少47%,35%和28%;2009年淋失量分别为1.4,1.3,3.0和5.1 kg/hm2;渗漏液中NO₃-N的浓度在第一季填闲并没有降低,到第二季时,已明显低于种植前期,以甜玉米处理浓度最低。②不同根层调控措施比较,2008年甜玉米传统种植、调理剂和秸秆还田处理在土壤剖面100cm的NO₃-N淋失量分别比休闲减少47%,83%和74%;而2009年只有传统种植低于休闲,其他两个处理高于填闲,调理剂和秸秆还田降低NO₃-N淋失的效果第二季最佳。（4）不同填闲作物和根层调控措施对下茬黄瓜的产量、生物量和吸氮量均为前茬休闲最大,但无显著差异。黄瓜收获时,所有处理0-200cm土体NO₃-N的累积均为负值,其中苋菜最高,甜高粱次之,休闲和甜玉米无显著差异;调理剂的负累积低于传统种植和秸秆还田处理。在NO₃-N表观平衡中,前茬休闲NO₃-N的损失量最低,但与前茬甜玉米和调理剂的差异不显著。在土壤剖面100cm处土壤溶液中NO₃-N变化较小,处理间变化趋势一致,说明一季黄瓜种植后,100cm处的NO₃-N浓度还受前茬填闲的影响,填闲作物的提氮效果持续到黄瓜生长结束。此处淋失量前茬休闲、甜玉米、苋菜和甜高粱分别为14.14,6.70,9.89和7.40kg/hm²,前茬休闲、传统种植、调理剂和秸秆还田分别是14.14,6.70,18.39和16.68kg/hm²。可以看出黄瓜在种植期间的大水大肥导致NO3-N淋失量均高于填闲种植期间。更多还原

【Abstract】 This research, adopting Sweet corn （Zea mays L.）, Amaranth （Amaranthus spp.）and sweet sorghum（Sorghum Linn.）as catch crops, studies different categories of catch crops as well as their control measures in root zone to carry on the field home position repairing experiments. With decreasing soil nitrate accumulation and leaching in root zone as a target, this research analyzes different categories of catch crops and the influence of control measures in root zone NO₃-N leaching, and reveals their influence on crop yield in the next quarter and soil profile NO₃-N, main results as follows:（1）The sweet corn was the best in biomass , N uptake, and the effect of soil profile NO₃-N reduction, with the reduction of NO₃-N being respectively 153.76 kg/hm2 and 605.70kg/hm2 in 2008 and in 2009.So from the perspective of balance of nitrogen, the loss of two quarters of catch crops 0-200cm soil NO₃-N was the highest in the terms of fallow; compared between the three kinds of catch crops, N loss planting with sweet corn was lowest in 2008, and then that of Amaranth in 2009 was the lowest, but there was little difference in that of Sweet corn.（P<0.05）.This result can explain that the growth of the Sweet corn could decrease accumulation of vegetable soil NO₃-N.（2）About biomass and N uptake with the measures of conditioner and straw have not substantial differences, but higher than measures of deep plowing. The accumulation of NO₃-N in soil profile after harvest of catch crop with the measures of fallow was the highest. Accumulation of NO₃-N with the measures of fallow was 90-100cm,while fallow was 120-140cm.In the variety of soil profile accumulation of NO₃-N, fallow was always in high residue. The effect of the three kinds of root layer conditioning agent on NO₃-N could fall in the large bugle stage of sweet corn（after planting 40 days）in NO₃-N,and maintains till harvest,but there was a peak at straw returning 60 days after sewing,from impact of depth we can see that the effect of conventional cultivation reaches 60cm,while conditioning agent and straw returning arrive at 80cm.（3）The trend of leaching amount of water and NO₃-N was similar. That in 2008 was higher than that in 2009, corresponding with raining in 2008.①compared with different kinds of catch crops,NO₃-N leakage of Sweet corn Amaranth and sweet sorghum was 1.9 kg/hm²,2.4 kg/hm²and 2.6 kg/hm² respectively in 2008,compared to fallow, that decrease by 47%,35% and 28% respectively;leaching reach 1.4 kg/hm²,1.3 kg/hm²,3.0 kg/hm² and 5.1 kg/hm² respectively in 2009; the content of NO₃-N in the leakage was not falling in the first quarters of fallow,but in second quarters,which was lower than that before planting clearly,the control measure of Sweet corn was the lowest.②compared with different control measures,NO₃-N leakages with three kinds of control measures in 100cm of soil root layer were reduced by 47%,83% and 74% separately than fallow treatment, and the leaching amount was lowest in soil structure conditioner treatment;in 2009, conventional cultivation was lower than fallow,while other two treatments were higher than treatment with catch crop,the effect of root layer conditioning agent and straw returning to low NO₃-N leaching was the best in second quarters.（4） In The effect of succeeding cucumber yield、N uptake and biomass of different kinds of catch crops and root layer conditioning agent, previous crops were always the best,without too clear difference. When cucumbers were harvested,all the treatment 0-200cm the accumulation of soil NO₃-N was negative,that of Amaranth was the highest,and followed by that of sweet sorghum,and that of fallow and Sweet corn has not clear difference;the accumulation of soil NO₃-N of root layer conditioning agent was less than that the measures of conventional cultivation and straw returning in apparent in the nitrogen balance,previous fallow NO₃-N losing was the lowest,compared with previous Sweet corn and root layer conditioning agent, without significant difference. In soil profile 100cm, the content of NO₃-N varies not too much, and the trend of treatments change was similar,which shows after cucumber,soil content of NO₃-N in 100cm was still under influence of previous crop,and catch crops provide nitrogen effect until the end of cucumber. At This point, leakage previous fallow Sweet corn、Amaranth and sweet sorghum arrive at 14.14 kg/hm²,6.70 kg/hm²,9.89 kg/hm² and 7.40kg/hm² respectively. The measures of previous fallow conventional cultivation, root layer conditioning agent and straw returning reach 14.14 kg/hm²,6.70 kg/hm²,18.39 kg/hm² and16.68kg/hm² respectively.It could be seen clearly that cucumber in a large fertilizer planting during the flooding caused NO₃-N leakage higher than that planted during the catch.更多还原