Water-extractable organic matter from sandy loam soils
Labile organic matter plays important roles in soil health and nutrient cycling because of its dynamic nature, and water-extractable organic matter is part of the soil labile organic matter.
In an article recently published in Agricultural & Environmental Letters, researchers report on the level and nature of water-extractable organic matter of sandy loam soils from a six-year potato crop rotation field experiment under the five management systems with rainfed or irrigation conditions.
The team found that crop rotation decreased the level of soil water-extractable organic matter in rainfed potato fields except when there was external input from manure compost. However, irrigation increased the level of water-extractable organic matter in management practices related to disease suppression, soil conservation, and soil improvement. The nature of this labile organic matter pool of potato soils was mainly decomposed and humified organic components whereas there were plant residues or compost incorporation in all treatments.
Results from this study suggest that cropping management practices that included crop rotation and irrigation stimulated the decomposition of the humic fraction in the soil organic matter pool. This implies healthier soil conditions with these management practices than continuous potato growth. Findings in this study would contribute to the overall goal of enhancing productivity and sustainability of the global potato industry.