Soil compaction in areas of maize used for silage with the application of wastewater

ABSTRACT The mechanical resistance of the soil to penetration (RP) was evaluated over two consecutive years in areas where off-season maize is produced for silage. Removal of the aerial part of the maize during the ensiling process leaves the soil exposed and subject to compaction, which may compromise a no-till system (NTS). The aim of this study therefore, was to monitor the RP of a soil under plant cover associated with the application of wastewater from pig farming (WPF) in areas of maize ensiling under NTS. The study was conducted in Matelândia, in the State of Paraná, employing seven management systems: soybean/silage/oats and turnip (SSOT); soybean/oats and turnip (SOT); soybean/silage/scarification + oats and turnip (SSSOT); soybean/silage and brachiaria (SSB); soybean/silage/oats (SSO); soybean and silage (SS) and soybean and maize (SM), repeated over two consecutive years. In the treatments that included WPF, 100 m3 ha-1 yr-1 were applied, split into two equal doses: one on the maize and the other on the cover crops. The experimental design was of randomised complete blocks (RCB), with four replications per treatment, and four samples per replication. The system with no cover crops had a higher RP; the 0.10 to 0.15 m layer of soil had the highest RP; whereas the application of WPF at a dose of 100 m3 ha-1 yr-1 decreased the RP.

摘要：本研究针对青贮用反季节玉米种植区，连续两年开展了土壤穿透阻力（Penetration Resistance，RP）的测定。青贮过程中移除玉米地上部分会使土壤裸露并易发生压实，这可能对免耕系统（No-till System，NTS）造成不利影响。因此，本研究旨在监测免耕系统（No-till System，NTS）下青贮玉米种植区中，配施养猪场废水（Wastewater from Pig Farming，WPF）的植物覆盖体系的土壤RP。试验于巴西巴拉那州马泰兰迪亚开展，设置7种管理体系：大豆/青贮/燕麦与芜菁（SSOT）、大豆/燕麦与芜菁（SOT）、大豆/青贮/浅松耕+燕麦与芜菁（SSSOT）、大豆/青贮与臂形草（SSB）、大豆/青贮/燕麦（SSO）、大豆与青贮种植（SS）以及大豆与玉米（SM），试验连续两年重复实施。在包含WPF的处理组中，按100 m³·ha⁻¹·yr⁻¹的用量施加该废水，分为两个等量剂量：一次施用于玉米，另一次施用于覆盖作物。试验采用随机完全区组设计（Randomised Complete Blocks，RCB），每个处理设置4次重复，每次重复采集4份土样。结果表明：无覆盖作物的体系土壤RP更高；0.10~0.15 m土层的RP最高；而施加100 m³·ha⁻¹·yr⁻¹的WPF可降低土壤RP。