Soil tare application in the rotation - yield, quality and N uptake of sugarbeet and wheat.

摘要

In the sugar factory of Euskirchen a procedure was developed for a thermal treatment and subsequent mechanical pressing of soil tare so that it can be applied to arable soils without any further storage. A strategy for utilization was tested where soil tare was applied in different heights (0, 2, 4, 8 cm) without changing the rotation. The effect of soil tare on yield and quality as well as N uptake of the plants and N supply of the soil was investigated also as long-term effect. The N applied with soil tare could be utilized well by the plants. Sugarbeet showed a positive response of yield and quality which exceeded the sole N effect even 4 years after the application of soil tare. The concentration of mineral N in soil was increased after application of soil tare, but not in the lower soil layers. Therefore, it can be assumed that with the amounts of soil tare tested the risk of N leaching is low when the soil is covered with plants. No difference occurred between the thermal and mechanical treatment of soil tare. The annual N mineralization of the unfertilized soil was as high as 190 kg N ha-1. The additional mineralization from soil tare reached 25 and 50 kg N ha-1 and was in tendency 4 years after the application higher than in the year directly after the application. These amounts of N have to be considered in the fertilizer recommendation. It is concluded that an utilization of soil tare with respect to ecological guidelines is possible in a sugarbeet/cereal rotation when the soil is covered throughout the whole year. Their professional use can contribute to the productivity of the site.