Effect of land-use change on water-stable aggregates and soil chemical properties within of two cultivated fields in khost province, Afghanistan

Conventional farming system may cause physical and chemical soil degradation. Plant residue retention can be used to improve soil aggregation and chemical properties. However, the effectiveness of plant residue retention in conventional farming (CF) system remains unclear. Therefore, we studied the influence of plant residue retention on the water-stable aggregates, mean weight diameter of water-stable aggregates, bulk density and soil chemical properties. Plant residue had a significant effect on the distribution of water-stable aggregates, with aggregates >4 mm and 2 mm being 10.3% and 15.4% higher with plant residue in combination with conventional farming (PRF) in 2018 than CF. Over time in 2018, the highest MWD was obtained in PRF plots, being on average 14.9% higher than in CF fields. In 2018, plant residue retention had significantly increased water content, which was 42.3% in PRF plots. In 2018, PRF and CF plots had 130.8 kg ha-1 and 102.8 kg ha-1 NO3-N respectively. PRF had 21.5% more soil NO3-N than CF plots. Using plant residue also increased soil P and K+ levels as compare to CF. These results indicated that retention of plant residue can increase water-stable macroaggregates, MWD and improve soil quality.