猕猴桃园和小麦—玉米轮作田两种土地利用方式对土壤养分状况的影响

为深入了解不同土地利用方式下土壤养分水平的差异及施肥和管理中存在的问题,选取陕西省周至县农耕区为研究区域,采用地统计分析和GIS相结合的方法,研究了猕猴桃园和小麦—玉米轮作田两种不同土地利用类型下土壤养分含量、养分相关性、空间变异特征及其分布格局。结果表明:猕猴桃园有机质、碱解氮、有效磷和速效钾4种养分含量分别为:(19.55±3.13)g·kg~(~(-1)),(80.58±14.69)mg·kg~(~(-1)),(23.37±6.09)mg·kg~(~(-1)),(102.79±12.74)mg·kg~(~(-1)),pH值为7.32±0.49;小麦—玉米农田有机质、碱解氮、有效磷和速效钾4种养分含量分别为:(19.43±2.63)g·kg~(~(-1)),(78.80±11.39)mg·kg~(~(-1)),(24.83±6.06)mg·kg~(~(-1)),(95.03±11.75)mg·kg~(~(-1)),pH值为7.41±0.58。猕猴桃园土壤有机质、碱解氮和速效钾含量均高于小麦—玉米农田,仅有效磷含量比小麦—玉米农田偏低。研究区主要养分要素的变异系数都处于10%~100%,属于中等空间变异性。在猕猴桃园中,有机质、碱解氮、有效磷、速效钾两两之间均呈极显著或显著正相关;在小麦—玉米农田,pH值与有机质表现出显著负相关。研究区土壤有效磷含量较为丰富,碱解氮含量处于中等偏高水平,有机质含量处于中等偏低水平,而速效钾含量总体缺乏。整体上猕猴桃园比小麦—玉米农田养分水平高,这主要与不同的田间管理和施肥状况有关。因此,今后应采取维持氮肥、控制磷肥、增加钾肥的措施,并十分重视有机肥的使用。此外,针对不同土地利用类型和土壤肥力状况进行分区培肥管理,普及科学施肥,提高肥料利用效率也是提升土壤肥力水平的重要措施。

Effects of kiwifruit trees planting and wheat-maize rotation planting on the status of soil nutrients

In order to investigate the differences in soil nutrients status under different land use patterns as well as the problems in fertilization and management, we employed joint methods of Geo-statistical analysis and GIS to study the content and spatial correlation of soil nutrients under two land use types of kiwifruit orchard and wheat-maize rotation farmland in Zhouzhi County, Shaanxi Province. The characteristics of spatial variability and distribution patterns of soil nutrients were also analyzed. The results showed that the content of organic matter, alkali-hydrolyzable nitrogen, available phosphorus and readily available potassium in kiwifruit orchards were (19.55±3.13) g·kg^-1, (80.58±14.69) mg·kg^-1, (23.37±6.09) mg·kg^-1, (102.79±12.74) mg·kg^-1 respectively, pH value was 7.32±0.49. The content of four nutrients in wheat-maize rotation farmland were (19.43±2.63) g·kg^-1, (78.80±11.39) mg·kg^-1, (24.83±6.06) mg·kg^-1, (95.03±11.75) mg·kg^-1 respectively, pH value was 7.41±0.58. The mean content of organic matter, alkali-hydrolyzable nitrogen, readily available potassium of kiwifruit orchards were higher than that of wheat-maize rotation farmland, only the content of available phosphorus was lower. The variation coefficient of all soil nutrients belonged to moderate spatial variability and they were between 10% and 100%. In kiwifruit orchards, organic matter, alkali-hydrolyzable nitrogen, available phosphorus, readily available potassium were positively correlated. In wheat-maize rotation farmland, the pH was negatively correlated with organic matter. The content of soil available phosphorus was abundant in studied area, the content of alkali-hydrolyzable nitrogen was slightly high, the content of organic matter was slightly low, and the content of readily available potassium was deficient. The nutrient level of kiwifruit orchards was relatively higher than that of wheat-maize rotation farmland as a whole, mainly associated with different management and fertilization status.