Poultry litter and fresh mulch of Elephant grass improve the organic potato production

ABSTRACT The organic production system for potato is usually limited by the occurrence of diseases and nutrient shortage. In these cases, fresh grass mulch and organic fertilization can interact in the foliar late blight infestation and increase the yield and quality of marketable potato tubers, in the organic production system. Aiming to validate this hypothesis, four poultry litter doses (0 Mg ha-1, 10 Mg ha-1, 20 Mg ha-1 and 30 Mg ha-1), which were incorporated into the soil at the pre-planting stage of organic grown potato combined with the presence and absence of fresh mulch (60 Mg ha-1) composed of chopped Elephant grass, were tested. The incorporation of poultry litter into the soil at the pre-planting of potato or the use of fresh grass mulch after the potato hilling inhibits the late blight infestation on leaves, in the organic system. The application of fresh grass mulch after the hilling operation enhances the effect of organic fertilization at the pre-planting of potatoes. The pre-planting application of poultry litter increases the yield and decreases the specific gravities of marketable potato tubers in association with fresh grass mulch. The use of poultry litter at pre-planting and fresh grass mulch improve the sustainable potato cropping in the organic production system.

摘要
马铃薯有机生产体系通常受病害发生与养分匮乏的制约。在该体系中，鲜草覆盖与有机肥配施可对叶片晚疫病侵染产生交互作用，进而提升商品马铃薯块茎的产量与品质。为验证该假说，本试验设置4个家禽垫料（poultry litter）施用量梯度：0 Mg·ha⁻¹、10 Mg·ha⁻¹、20 Mg·ha⁻¹及30 Mg·ha⁻¹，于有机马铃薯种植前将其翻施入土中，并搭配2个鲜覆盖处理——覆盖量为60 Mg·ha⁻¹的切碎象草（Elephant grass）覆盖与无覆盖。
试验结果显示：在有机生产体系中，于马铃薯种植前将家禽垫料翻施入土，或在培土后施用鲜草覆盖，均可抑制叶片晚疫病侵染；培土后施用鲜草覆盖可强化种植前有机肥的施用效果；当与鲜草覆盖配施时，种植前施用家禽垫料可提升商品马铃薯块茎的产量，但会降低块茎比重；种植前施用家禽垫料搭配鲜草覆盖，可优化有机生产体系下马铃薯的可持续种植模式。