Microbial soil health with legume crop rotation in organic greenhouse production

Sammanfattning

The purpose of this study is to examine the potential effect the different legume crop rotations have on the microbial soil health in organic greenhouse production. To answer the purpose the following hypothesis was formulated: the microbial soil health is differently affected by the two different legume crop rotations. The method in this study was performed by observing and collecting data from two legume crop rotations: sugar pea (Pisum sativum var. saccharatum) as a sole crop, and intercropping cucumber (Cucumis sativus) as main crop with crimson clover (Trifolium incarnatum) as a green manure crop. Three sets of soil samples were collected to analyse the dynamic and health of the soil before, during and after the growing cycle. The analysis of microbial soil health was based on five indicators: microbial activity, soil respiration, soil protein, available carbon and nutrient analysis. Findings - The results showed a significant difference in sampling dates, but no significant difference was shown between crop rotations. The results also showed that legumes have an effect on the amount of nitrate found in the soil. Hence, this study shows a significant correlation between total amount of nitrate and microbial activity, total amount of nitrate and soil protein, microbial activity (FDA) and respiration. The main finding of this study is that there was not a significant difference in the microbial soil health between the two crop rotations, sole legume crop and intercropped main crop with a legume crop. Thus, the hypothesis for the study was rejected. This study contributes to the knowledge of legumes effect on the microbial soil health in organic greenhouse production, the findings also show the importance of a holistic and societal view taking into consideration factors regarding sustainability and economics.