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在盐渍化土壤中,普遍存在土壤结构性和养分状况差以及土壤酶活性低等现象。这种现象主要是由于土壤中过量的交换性钠离子和较高的土壤pH所引起。长期施用有机肥(牛粪)是一项提升盐渍化土壤质量的重要措施。本研究依托东北农业大学盐碱土改良长期定位试验站,以腐熟的牛粪为改良材料,依据牛粪施用年限共设置5个处理,采用完全随机区组设计,每处理3次重复,供试作为玉米,各处理分别为:施用牛粪2年、6年、13年和18年,以不施用牛粪的盐渍化土壤作为对照。分别测定各处理的土壤理化指标和酶活性。采用因子分析法与土壤质量指数法评价长期施用有机肥对盐渍化土壤质量的影响。研究结果表明:长期施用有机肥能够改善盐渍化土壤的物理性状、提高土壤养分状况、降低土壤pH和盐分以及增加土壤酶活性。根据特征根>1原则,经因子分析后可提取2个公因子,分别表征“土壤结构性”(因子1)和“土壤盐碱性质”(因子2)。与未施用有机肥的土壤相比,施用有机肥13年和18年的土壤具有较好的土壤结构性和较低的盐碱性质,而施用有机肥2年和6年的土壤仅具有较低的盐碱性质。比较土壤质量指数(SOI)可知:盐渍化土壤质量随有机肥施用年限而增加,有机肥施用18年处理的土壤质量最高。总之,土壤结构性差和盐碱性质高是影响松嫩平原盐渍化土壤质量的关键限制因子,其中以土壤结构性差最为主导;土壤容重、pH和盐分的降低是长期有机培肥措施下盐渍化土壤质量得以提升的重要特征,尤其是以土壤容重的降低最为重要。
In salinized soils, there is a widespread phenomenon of poor soil structure and nutrient status and low soil enzyme activity. This phenomenon is mainly caused by excess soil exchangeable sodium ions and higher soil pH. Long-term application of organic fertilizer (cow dung) is an important measure to improve the quality of salinized soil. This research relies on the modified saline-alkali soil long-term positioning experimental station of Northeast Agricultural University, using the decomposed cow dung as the improved material and 5 treatments according to the dwelling age of cow dung, using completely randomized block design with 3 repetitions per treatment for Maize were treated with cow dung at two, six, thirteen and eighteen years respectively. Salinized soil without cow dung was used as a control. Soil physical and chemical indexes and enzyme activities of each treatment were determined. Using Factor Analysis and Soil Quality Index to Evaluate the Effect of Long - term Application of Organic Fertilizer on Salinized Soil Quality. The results showed that long-term application of organic manure could improve the physical properties of salinized soils, increase soil nutrient status, lower soil pH and salinity, and increase soil enzyme activities. According to the principle of eigenvalue> 1, two common factors can be extracted after factor analysis to characterize “soil structure ” (factor 1) and “soil salinization property ” (factor 2). Compared with the soil without organic fertilizer, the soil with organic fertilizer for 13 years and 18 years had better soil structure and lower salinization properties, while the soil with organic fertilizer for 2 years and 6 years had only lower The salty-alkaline nature. Comparing soil quality index (SOI) shows that the quality of salinized soil increases with the age of manure application, and the soil quality of organic manure treated for 18 years is the highest. In conclusion, poor soil structure and high salinization are the key limiting factors affecting the quality of salinized soils in the Songnen Plain, of which the soil structure is the most dominant. The reduction of soil bulk density, pH and salinity is the result of long-term organic fertilization An important feature of improved soil quality is the most important of which is the reduction of soil bulk density.