分散经营条件下烤烟精准养分管理研究

【目的】西南烤烟种植区的典型特征是"缓坡条件"和"分散经营",基于自然地块的变量施肥技术体系,研究分散经营条件下烤烟养分分区管理,以探讨分散经营条件下作物精准施肥的经济效益和应用可行性。【方法】分散经营土壤养分管理分区的基本步骤:计算土壤养分插值,以地块为单元统计土壤养分,依据施肥模型针对地块进行肥料养分推荐、聚类分析地块肥料养分,形成针对地块的养分管理分区。在云南宜良县,以50×50 m的网格进行土壤取样,应用地统计方法进行土壤养分空间变异分析、Kriging方法进行空间插值、空间叠加分析方法统计地块养分、聚类分析方法建立养分管理分区,大田试验检验养分分区管理方法的应用效果。【结果】研究结果表明,试验地块为中等肥力,土壤养分存在区域分布特征,适合分区养分管理。地统计分析显示,土壤养分变异主要来源于结构因素,可以进行地统计分析和空间插值,满足精准养分分区管理的要求。无机氮的有效变程最小,控制采样密度,缓坡农田和分散经营条件下精准养分管理的网格采样间距在50 m左右。根据空间分析结果,结合施肥指标体系,提出了111块烟田的推荐施肥量,并通过聚类分析的方法将111块农田的肥料养分推荐量分为8个管理区。与对照相比,烤烟精准养分分区管理可以节约氮、磷肥料分别为10.7%、10.3%,氮、磷养分投入分别节约成本43.2yuan/hm2、50.0 yuan/hm2,因增加钾素养分投入增加成本6.9 yuan/hm2,累计节省肥料成本86.3 yuan/hm2。烤烟产量、上等烟比例、均价、产值均有增加,其中,产量增加幅度6.7%~14.5%,平均增产10.6%;上等烟比例增加幅度4.2%~13.0%,平均增加7.3%;均价增加幅度0.13~0.54 yuan/kg,平均增加0.48 yuan/kg;产值增加幅度7.50~18.3%,平均增加14.0%;与常规施肥相比,分散经营条件下烤烟精准养分管理使烤烟增产增收5454.63 yuan/hm2,节本增效5140.9 yuan/hm2。【结论】以地块为操作单元建立养分管理分区的方法不仅能够节省肥料,增加农田收益,还能够有利于分散经营农户组织实施,对精准施肥技术应用具有理论和实践意义。

Research on the field-specific nutrient management of flue-cured tobacco in condition of decentralized operation

【Objectives】The study aimed to research the method of soil nutrient interpolation and management zone based on soil nutrient variability and nature operation unit, which is on condition of decentralized operations and hilly-sloppy lands for planting tobacco in southwest China. 【Methods】 Soil nutrient interpolation and management zone was established by the empirical study. On condition of diversified management, the basic steps of soil nutrient precise management and partition were put forward without the support of variable machine equipment, which included soil nutrition interpolation, soil nutrient statistics taking the separate plot as a unit, fertilizer formula recommended according to the fertilizer model, and plot nutrient management based on cluster analysis of fertilizer nutrient. In Yiliang county of Yunnan Province, soil samples were collected every 50×50 m on farmland with typical production organization and topography. Data were analyzed by geographic statistics for spatial variability of soil nutrients and by Kriging for spatial interpolation and by spatial overlay analysis statistics for fertilization and by clustering analysis method for nutrient management zone establishment. Effect of regionalized nutrient management method was verified through the field trial. 【Results】 The experimental field belongs to medium fertility, and soil nutrients have regional distribution characteristics and suitable for the partition of nutrient management. Soil nutrient variations are mainly from the structural factors, which can carry out statistical analysis and spatial interpolation to meet the requirements of precision nutrient management. The effective range of inorganic nitrogen is the minimum, which controls the sampling density, and the grid sampling spacing is about 50 m of precision nutrient management under the condition of slope farmland and decentralized management. According to the spatial analysis results, combined with the index system for fertilization, the fertilization rates of the 111 fields are proposed, and the fields are divided into 8 management areas through the method of clustering analysis. The application steps in gentle slope fields show that compares with the farmers’ conventional fertilization, the application amounts of N and P fertilizers through the precise nutrient management could be decreased by 10.7%, 10.3%, and the fertilization costs of nitrogen, phosphorus and potassium nutrients are saved by 43.2 yuan/hm2, 50 yuan/hm2 and -6.9 yuan/hm2, with the total saved cost of 86.3 yuan/hm2. The yield, output value, average price and high class leaf proportion are increased. The yield is increased by 6.7%-14.5% with an average increase of 10.6%, the proportion of superior leaves is increased by 4.2% to 13% with an average increase of 7.3%, the price is increased by 0.13-0.54 yuan/kg with an average increase of 0.48 yuan/kg, and the output value is increased by 7.50%-18.3%, with an average increase of 14%. The production is increased by 5454.63 yuan/hm2, and the net benefit is increased by 5140.9 yuan/hm2. 【Conclusions】 The method of nutrient management zones established by the operation unit can not only save fertilizer and increase farm income, but also is conducive to the spread of farmers organization, which has theoretical and practical significance to the application of precision fertilization technology.