Influence of Agricultural Service Crops on the fluctuations of the soil mineral composition

Summary

Usage of organic fertilizers and agricultural service crops (ASC) are the main tools to ensure soil fertility to obtain high quality organic vegetables. The most popular used ASCs are green manure, catch-crop, and living mulch. Efficiency of ASC crops under Latvia agro-ecological conditions for vegetable growing has not been investigated till now. Field trials where established in the Institute of Agricultural Resources and Economics during the season of 2015/2016 in Dižstende, Latvia with the aim to clarify the influence of ASC application on cabbage and onion crops yield and compare with traditional soil management systems: (i) green manure - in which ASC biomass of winter rye (Secale cereale L.) and winter rape (Brassica napus L.) was incorporated in the soil in the spring, (ii) roller crimper – in which ASC rye and rape was flattened by a roller-crimper before vegetable planting to create a mulch layer. These four ASC treatments were compared with: control 1 (no ASC, with soil tilled before crop planting) and control 2 (cattle manure ploughed into the soil before vegetable planting). There was not stated sharp difference in agrochemical composition between tested soil management variants. More expressed are differences between vegetables – cabbage has reduced nitrate content in the soil, whereas onion has not reduced nitrates content in the soil almost at all. From the one season results we can conclude that ASC crops have some positive influence on the maintenance of mineral nutrients balance in vegetable cropping systems, which has to be investigated for longer time period to find particular regularities.