KMS Institute of soil and water conservation Chinese Academy of Sciences
|Place of Conferral||北京|
|Keyword||春玉米 硝态氮淋溶 阻控措施 黄土高原|
1. 氮肥在一定范围内能够增加玉米产量，合理施用氮肥可以防止硝态氮的淋溶累积。不同施氮量条件下，春玉米的地上部生物量和产量均随施氮量的增加而增加，但氮肥施用达到一定量后，春玉米的产量趋稳。本试验中，氮肥用量超过200kg N / hm2时，春玉米产量不再增加。说明施氮量达到200kg N / hm2时，氮肥已经接近最大的增产效果。收获期土壤剖面0～200 cm范围内的硝态氮含量及累积量均随施氮量的增加而增加，当施氮量大于160 kg / hm2时，土壤中0～200cm范围内的硝态氮累积量就会产生跃变，施氮160 kg / hm2处理的土壤剖面0～200cm范围内的硝态氮累积量较不施氮肥处理仅增加了10.69 kg / hm2，而施氮200 kg N /hm2处理和施氮250 kg N /hm2处理的土壤剖面 0～200cm范围内的硝态氮累积量较不施氮肥处理分别增加了66.26 kg / hm2和 96.55 kg / hm2。
2. 减量施氮和秸秆深埋均能在一定程度上增加春玉米的产量，减少硝态氮向土壤深层的淋溶累积。常规栽培条件下，减量施氮 (CR1) 处理的产量较传统施氮(CON1)处理增加了1259.62 kg / hm2，且CR1处理的剖面 0~200cm范围内的硝态氮累积量较CON1处理减少了25.73%；秸秆深埋条件下，减量施氮 (CR2) 处理的产量较传统施氮(CON2)处理增加了2523.04 kg / hm2，且CR2处理土壤剖面0~200cm范围内的硝态氮累积量较CON2处理减少了25.24%；此外，CR2处理的产量较CON1处理增加了2878.04 kg / hm2， CR2处理的剖面0~200cm范围内的硝态氮累积量较CON1处理减少了30.17%。说明减量施氮及秸秆深埋都能在一定程度上减少硝态氮的淋溶累积。
3. 添加不同浓度的硝化抑制剂 (DCD) 对春玉米的产量和土壤硝态氮淋溶累积的影响不同。4个添加硝化抑制剂处理 (CRN1% 、CRN5% 、CRN10%、 CRN15%) 的DCD添加量分别为施氮量的1%、5%、10%、15%。与不添加硝化抑制剂 (CRN0%)处理相比，添加硝化抑制剂处理的产量有一定下降，但在统计学上无显著差异(P > 0.05)。四个添加硝化抑制剂处理0~200cm范围内的硝态氮剖面累积量均低于不添加硝化抑制剂 (CRN0%) 处理的累积量，分别减少了55.85%、43.24%、22.78%和18.54%，说明硝化抑制剂在一定程度上能够抑制尿素的分解，减少硝态氮的淋溶累积。硝化抑制剂对土壤硝态氮深层累积的阻控效果随着添加浓度的增大而减弱。在本试验中，硝化抑制剂的添加浓度为1%时，其对硝态氮深层累积的阻控效果最为显著。
4. 在同等施氮量条件下，尿素中掺混缓释肥处理在不减产的情况下，有利于减少土壤剖面的硝态氮淋溶累积。与全尿素处理 (CRS4) 相比，CRS1处理（尿素占35%）、CRS2处理（尿素占50%）及CRS3处理（尿素占65%）的产量低于CRS4处理，但在统计学上没有显著性差异(P > 0.05)。与CRS4处理相比，CRS1、CRS2、 CRS3处理0 ~ 200 cm范围内的硝态氮累积量均低于CRS4处理，其中100 ~ 200 cm范围内的硝态氮累积量明显下降，降幅分别为60.81%、64.97% 和39.92%。说明尿素中掺混缓释肥能够减缓硝态氮向深层的淋溶累积。
|Other Abstract||The application of nitrogen fertilizer has increased rapidly since the early 1980s. Relevant studies have shown that the amount of fertilization has a great impact on the accumulation of NO3--N in dry land, and the effect of NO3--N accumulation on 0-2 m soil layer is particularly prominent. In order to study the mechanism of nitrate nitrogen leaching and control in rain-fed agriculture areas in the southern Loess Plateau, the field experiment was carried out in the agricultural ecological test station of the Changwu Loess Plateau of Chinese Academy of Sciences. Through the N application rate gradient, reducing nitrogen, straw buried deep, adding nitrification inhibitors concentration, urea and slow-release fertilizer mixing proportion of research, analysis of the change of soil NO3--N content and spring maize growth situation under different factors, to investigate the effect of different factors on soil nitrate-N in spring maize field. The test results are as follows:|
1. Nitrogen fertilizer can increase the yield of maize in a certain range, reasonable application of nitrogen fertilizer can prevent the leaching accumulation of nitrate nitrogen. Under different nitrogen application conditions, the biomass and yield of spring maize increased with the increase of nitrogen fertilizer, but the yield of spring maize stabilized after the application of nitrogen fertilizer reached a certain amount. In this experiment, the yield of spring maize no longer increased when the amount of nitrogen fertilizer exceeded 200 kg N/hm2. The content and accumulation of nitrate nitrogen within the range of 0-200cm in the soil profile at harvest time increased with the increase of N application rate, while N application rate is more than 160 kg/hm2, 0 ~ 200 cm soil NO3--N accumulation amount will generate jump, 160 kg/hm2 nitrogen treatment of soil NO3--N accumulation amount increased only 10.69 kg/hm2 compared with no nitrogen treatment. The nitrogen content of the soil profile (0 ~ 200cm) treated with nitrogen 200 kg N /hm2 treatment and 250 kg N /hm2 treatment increased by 66.26 kg/hm2 and 96.55 kg /hm2 respectively.
2. Reduced nitrogen application and deep burial of straw can increase the yield of spring maize to some extent, and reduce the leaching of nitrate nitrogen into the deeper layers of the soil. Under conventional cultivation conditions, the yield of reduced (CR1) treatment increased 1259.62 kg/hm2 compared with the conventional (CON1) treatment, and the cumulative amount of nitrate nitrogen profiles (0~200cm) of CR1 treatment decreased by 25.73% compared with that of CON1 treatment. Under deep straw stalk condition, the yield of reduced (CR2) treatment increased 2523.04 kg/hm2 compared with conventional (CON2) treatment, and the cumulative amount of nitrate nitrogen profile (0~200cm) of CR2 treatment decreased by 25.24% compared with that CON2 treatment. In addition, the yield of CR2 treatment was increased by 2878.04 kg/hm2 compared with CON1 treatment. The cumulative amount of nitrate nitrogen profile (0~200cm) treated by CR2 was reduced by 30.17% compared with CON1 treatment. It shows that reducing nitrogen application and deep burying of straw can reduce the leaching accumulation of nitrate nitrogen to a certain extent.
3. The addition of different concentrations of nitrification inhibitors (DCD) has different effects on the yield of spring maize and soil nitrate-nitrogen leaching accumulation. The treatment of DCD added by four addition of nitrification inhibitors (CRN1%, CRN5%, CRN10%, CRN15%) was 1%, 5%, 10%, and 15% of the amount of nitrogen applied. Compared with the treatment without addition of nitrification inhibitor (CRN0%), the addition of nitrification inhibitor treatment had a certain decrease, but there was no statistically significant difference (P > 0.05). The cumulative nitrate nitrogen in the profiles of 0–200 cm with four addition nitrification inhibitors were lower than those without the addition of nitrification inhibitors (CRN0%), which were reduced by 55.85%, 43.24%, 22.78%, and 18.54%, respectively. This shows that nitrification inhibitors can inhibit the decomposition of urea to a certain extent and reduce the accumulation of nitrate nitrogen leaching. The inhibitory effect of nitrification inhibitors on the deep accumulation of nitrate in soil decreased with the increase of the concentration. In this experiment, when the addition concentration of nitrification inhibitor was 1%, its effect on the deep accumulation of nitrate nitrogen was the most significant.
4. Under the same nitrogen application rate, the addition of slow-release fertilizer in urea can help to reduce the accumulation of nitrate-nitrogen leaching in the soil profile without reducing production. CRS1 treatment (35% urea), CRS2 treatment (urea 50%), and CRS3 treatment (urea 65%) yield less than CRS4 treatment compared to total urea treatment (CRS4) but was not statistically significant Sexual differences (P > 0.05). Compared with CRS4 treatment, the accumulation of nitrate nitrogen in CRS1, CRS2, and CRS3 within the range of 0 ~ 200 cm was lower than that of CRS4 treatment. The cumulative amount of nitrate nitrogen in the range of 100 ~ 200 cm was significantly decreased, which was a drop of 60.81. %, 64.97%, and 39.92%. This shows that the slow-release fertilizer can slow down the leaching of nitrate from the deep layer.
Key Words: Spring maize, Nitrate nitrogen leaching, Controlling Measures, Loess Plateau
|董强. 黄土高原南部春玉米地土壤硝态氮淋溶的阻控措施研究[D]. 北京. 中国科学院研究生院,2018.|
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