日光温室栽培下石灰性土壤镁素供应状况研究

发布时间：2018-07-03 00:35

本文选题：日光温室 + 养分累积　；参考：《西北农林科技大学》2017年硕士论文

【摘要】：日光温室蔬菜种植在我国北方地区近年来发展迅速,在冬春蔬菜生产淡季保证正常蔬菜供应方面发挥了重要作用。但生产中存在为追求高产而盲目过量施肥问题,严重阻碍了这一产业的健康持续发展。近年来,在北方石灰性土壤种植区频频出现温室番茄缺镁症,且随栽培年限的增加有加重的趋势,一些研究表明,这一症状的出现与土壤养分过量累积尤其是钾离子的过多积聚密不可分。因此,本研究通过调查分析不同栽培年限温室土壤钾、钙、镁的含量及其比例的变化、施用镁肥对番茄产量及土壤中钾、钙、镁含量的影响,以期揭示日光温室土壤中钾、镁等养分含量及比例的变化及其与番茄生长的关系,为石灰性土壤缺镁作物的合理施肥提供科学依据。通过研究得到了以下主要结论:(1)通过对蔬菜主要产区-陕西省泾阳县云阳镇70座日光温室施肥情况的调查及对30座温室土壤样品的测定分析,结果表明:不同温室间施肥量差异很大,一季作物的氮、磷、钾化肥养分的投入平均为651 kg N/hm2、485 kg P2O5/hm2和855 kg K2O/hm2,养分投入量明显偏高;温室土壤耕层速效养分与种植年限存在正相关性,水溶性养分随栽培年限的增加而增加,水溶性K/Mg随种植年限的增加而增加,Ca/K随种植年限的增加而降低,离子间比例失衡问题突出。(2)以杨凌大寨设施栽培基地的7座日光温室为研究对象,进行了增施镁肥试验。结果表明:土壤钾素含量始终保持在较高水平,增施镁肥后,增加了土壤交换性和水溶性镁的含量。随着番茄生育期的推后,土壤镁含量和交换性镁饱和度随着镁用量的增加有增加的趋势。番茄产量与土壤镁含量可以用二次曲线拟合,与土壤钾含量呈线性负相关关系。土壤的K/Mg比例均大于0.4,存在钾离子抑制镁离子吸收的潜在风险,由于土壤钾含量过高,单施镁肥后难以有效矫正土壤阳离子的比例。(3)通过设置K、Mg两个因素,每个因素3水平的盆栽试验,研究了不同钾、镁用量对番茄生长、养分吸收及土壤养分的影响。结果表明:钾镁配施增加了番茄植株的干物质量,高钾用量降低了番茄的株高和茎粗。随钾用量的增加,番茄植株各部的钾浓度增加,而各部分的镁含量有降低的趋势,尤其降低了果实和叶片中的镁浓度,同时高钾水平下的番茄产量显著的低于低钾水平。土壤交换性钾、镁含量都随钾、镁施用量的增加而增加,K/Mg比值在高钾水平(K2)时比不施钾(K0)高出20.7%。
[Abstract]:Vegetable cultivation in solar greenhouse has developed rapidly in the north of China in recent years. It plays an important role in the production of vegetables in winter and spring to ensure the normal vegetable supply. However, the problem of blind excessive fertilization in order to pursue high yield in production seriously hinders the healthy and sustainable development of this industry. In recent years, in the calcareous soil growing area of northern China, tomato magnesium deficiency in greenhouse has been frequently appeared, and it has an aggravating trend with the increase of cultivation years. Some studies have shown that, The occurrence of this symptom is closely related to the excessive accumulation of soil nutrients, especially the excessive accumulation of potassium ions. Therefore, by investigating and analyzing the changes of potassium, calcium and magnesium contents and their proportions in greenhouse soils with different cultivation years, the effects of applying magnesium fertilizer on tomato yield and potassium, calcium and magnesium contents in soil were studied in order to reveal the potassium content in greenhouse soil. The change of magnesium content and proportion and its relationship with tomato growth provide scientific basis for rational fertilization of magnesium deficient crops in calcareous soil. The main conclusions are as follows: (1) the investigation of fertilization in 70 solar greenhouses in Yunyang Town, Jingyang County, Shaanxi Province, and the determination and analysis of 30 greenhouse soil samples were carried out. The results showed that there was a great difference in fertilization amount among different greenhouses. The average input of nitrogen, phosphorus and potassium fertilizer was 651 kg N / hm ~ (2) N / m ~ (2485) kg P _ 2O _ 5 / hm ~ (2) and 855 kg K _ 2O _ (2) / hm ~ (2). There was a positive correlation between soil available nutrients and planting years in greenhouse soil, water soluble nutrients increased with the increase of cultivation years, and water soluble K / mg increased with the increase of planting years, and decreased with the increase of planting years. The imbalance of the ratio between ions is very serious. (2) the experiment of increasing magnesium fertilizer was carried out in 7 solar greenhouses in Yang Ling Dazhai facility cultivation base. The results showed that the content of potassium in soil remained at a high level, and the content of soil exchangeable and water-soluble magnesium increased with the application of magnesium fertilizer. With the development of tomato, the content of magnesium and the saturation of exchangeable magnesium increased with the increase of the amount of magnesium. Tomato yield and soil magnesium content can be fitted by quadratic curve, and there is a linear negative correlation between tomato yield and soil potassium content. The K / mg ratio of soil is greater than 0.4, and there is a potential risk that potassium ion can inhibit the absorption of magnesium ion. Because of the high potassium content in soil, it is difficult to correct the ratio of cations in soil after applying magnesium fertilizer alone. (3) two factors, K ~ (+) mg and K _ (+) mg, can not be effectively corrected by applying magnesium fertilizer alone. The effects of different potassium and magnesium levels on tomato growth, nutrient uptake and soil nutrients were studied in pot experiments at each factor 3 level. The results showed that the application of potassium and magnesium increased the dry matter quality of tomato plant, and decreased the plant height and stem diameter of tomato with high potassium application rate. With the increase of potassium application, the potassium concentration in all parts of tomato plants increased, but the magnesium content in different parts decreased, especially in fruits and leaves, and the yield of tomato at high potassium level was significantly lower than that at low potassium level. The content of exchangeable potassium and magnesium in soil increased with the increase of potassium and magnesium application rate, and the ratio of K / mg increased 20.7% at high K _ 2 level (K _ 2) than that without K _ 0 application.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S158

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