Intercropping in potato production.

摘要

Two-year field trials at Bremervorde in Lower Saxony, Germany were conducted to study the effects of eight different intercrops in the potato varieties Saturna and Milva. Highest marketable yields were found with oilseed radish and annual ryegrass: 112% and 113% of control (fallow). There were also two types of cultivation tested: ploughing and deep hoeing (grubber). The plough produced better incorporation and marketable yields in all treatments. Starch yields showed similar tendencies, however fallow and plough also produced good results. Yield response was influenced by nitrogen dynamics. Highest N-uptake in tubers was with red clover, winter vetch, oil radish, blue lupins and phacelia. It appears that the more modern technique of mulching (grubber) which produces a good looking, fertile land has not such a good nitrogen efficiency as the traditional ploughing technique, which buries the organic matter deeper into the soil. The economic implications of inter- or cover-crops are shown in a final table. Oil radish, winter rape, lupins and winter vetch are all economically viable in the subsequent potato crop, producing higher marketable yields then variable cost, however only with ploughing not mulching. Environmental or longer term rotational benefits were not measured.