苏北沿海滩涂盐肥耦合对甘薯生长及土壤氮素营养的影响

发布时间：2018-08-19 12:13

【摘要】：【目的】在沿海滩涂种植甘薯不仅可提供丰富的粮食资源,还可以充分利用宝贵的沿海滩涂土地资源。本文重在阐明在苏北沿海滩涂上盐肥耦合对甘薯生长及土壤氮素营养的影响。【方法】本文在盐碱地上通过正交试验设计进行田间试验,研究了在不同土壤盐分上增施氮肥,甘薯及土壤氮素营养的盐肥耦合效应。【结果】(1)1.0~2.1 g/kg(S_2)的土壤盐分水平下,甘薯生长与0.5~1.0 g/kg(S_1)盐分水平差异不显著。盐分增大到2.1~3.2 g/kg(S_3)、3.2~4.0 g/kg(S_4)水平,甘薯生长受到抑制。增施氮肥后,土壤盐分的抑制作用得到显著缓解,甘薯各项生长指标及鲜薯产量呈现先升后降的趋势。经盐肥耦合作用,土壤盐分为1.0~2.1 g/kg,施氮量为50 kg·hm~(-2)的种植条件(S_2N_2)最有利于甘薯的生长和鲜薯产量的积累。(2)土壤养分含量随着盐分的增大而下降。氮肥的施入可显著提高土壤养分,在50 kg·hm~(-2)(N_2)、100 kg·hm~(-2)(N_3)水平下,土壤有效氮、全氮及微生物氮含量显著提高。0.5~1.0 g/kg(S_1)、1.0~2.1g/kg(S_2)的土壤盐分上氮肥的增产效应较显著,且土壤有效氮的氮肥增产效应大于土壤全氮含量。(3)NAG、LAP活性随着土壤盐分、施氮量及甘薯生长期的变化而变化。甘薯的生长促进了土壤NAG、LAP活性的提高。0.5~1.0 g/kg(S_1)-2.1~3.2 g/kg(S_3)土壤盐分下,甘薯生长期30 d之前,随着氮肥施用量的增加,NAG、LAP活性变化不显著。当生长期达到30 d时,LAP活性提高,酶活呈现N_3N_2N_4N_1的趋势,且差异显著。当生长期达到60~90 d时,各施氮量下的NAG、LAP活性差异显著提高,呈现N_3N_2N_4N_1的趋势。当生长期达到125 d时,NAG活性开始下降,LAP活性仍然呈现逐步上升的趋势。3.2~4.0 g/kg(S_4)土壤盐分下,随着施氮量的增加,NAG、LAP活性变化不显著。【结论】在盐碱地上增施氮肥,其土壤盐分与肥料养分的耦合作用对甘薯的生长发育、鲜薯产量、土壤酶活及养分产生了一系列的影响,包括:土壤盐分为1.0~2.1 g/kg,施氮量为50 kg·hm~(-2)的种植条件最有利于甘薯的生长和鲜薯产量的积累;种植甘薯及增施氮肥能够显著提高土壤NAG、LAP酶活性,增加盐碱地土壤养分,从而促进沿海滩涂生态修复,改善沿海滩涂生态环境。
[Abstract]:[objective] planting sweet potato in coastal beach can not only provide rich food resources, but also make full use of valuable land resources. In this paper, the effect of salt and fertilizer coupling on sweet potato growth and soil nitrogen nutrition was expounded. [methods] the field experiment was carried out on saline-alkali soil to study the application of nitrogen fertilizer on different soil salts. The salt-fertilizer coupling effect of sweet potato and soil nitrogen nutrition. [results] (1) under the soil salt level of 1.0 ~ 2.1 g/kg (SSP _ 2), the growth of sweet potato was not significantly different from that of 0.5 ~ (-1) g/kg (S _ (1). The growth of sweet potato was inhibited by the increase of salt content to 2.1 ~ 3.2 g/kg (S _ 3) and 3.22 ~ (4) g/kg (S _ (4). The inhibition of soil salt content was significantly alleviated after the application of nitrogen fertilizer, and the growth indexes of sweet potato and the yield of fresh potato increased first and then decreased. Through the salt-fertilizer coupling, the soil salt content was 1.0 ~ (2) g 路kg ~ (-1), and the nitrogen application rate was 50 kg hm ~ (-2). (2) the soil nutrient content decreased with the increase of salt content, and the growth of sweet potato and the accumulation of fresh potato yield were most favorable. Application of nitrogen fertilizer could significantly improve soil nutrients. At the level of 50kg hm-2 (N2) (N2) and 100kg hm-2 (N3), the contents of available nitrogen, total nitrogen and microbial nitrogen in soil increased significantly by 1.0 g/kg (S1) 1.0 g / kg (S2) / kg (S2). (3) NAGN LAP activity changed with the change of soil salt, nitrogen application rate and sweet potato growth period. The growth of sweet potato promoted the increase of NAGN LAP activity in soil. Under the salt content of soil salt, the activity of NAGLAP did not change significantly with the increase of nitrogen application rate. When the growth period reached 30 days, the activity of lap increased, and the activity of enzyme showed the trend of N_3N_2N_4N_1, and the difference was significant. When the growth period reached 60 ~ 90 days, the difference of NAGLAP activity under different nitrogen application rates increased significantly, showing the trend of N_3N_2N_4N_1. When the growth period reached 125d, the activity of nag began to decrease and the activity of lap still showed an increasing trend. Under soil salt content of 3.2N 4.0 g/kg (S4), the activity of nag lap did not change significantly with the increase of N application rate. [conclusion] nitrogen fertilizer was applied on saline soil. The coupling effect of soil salt and fertilizer nutrient has a series of effects on the growth and development of sweet potato, yield of fresh potato, soil enzyme activity and nutrient. The results showed that the soil salt content was 1.0 ~ 2.1 g / kg, the nitrogen application rate was 50 kg hm ~ (-2), the growth of sweet potato and the accumulation of fresh potato yield were most favorable, and planting sweet potato and applying nitrogen fertilizer could significantly increase the activity of NAGN LAP enzyme and increase the soil nutrient in saline-alkali soil. In order to promote the ecological restoration of coastal beach, improve the ecological environment of coastal beach.
【作者单位】：江苏沿海地区农业科学研究所;
【基金】：盐城市农业科技创新专项引导资金(YK2015013)
【分类号】：S158;S531

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