The Effect of Mulching and Non-Mulching on Soil Erosion, Nutrient Loss, and C factor Using Lysimeter under Double Cropping System

Abstract

Evaluating soil erosion becomes critical because of climate changes, sporadic and localized raining events over years in Korea. The objective of this study was to evaluate the amount of soil erosion and to calculate C factor under different crop management system. Six lysimeters were installed with 13% slope at Muan, Jeon-Nam, Korea. Four crops, onion, sesame, garlic, and sweet potatoes were grown consecutively. Treatments were with and without mulching for onion, and with and without mulching and control (no crop) for the others. All crops grew better under mulching than non-mulching treatments. The amount of eroded soil under mulching treatment reduced 2,280, 8,076, 2,337, 2,262.9 kg ha-1 for onion, sesame, garlic, and sweet potatoes, respectively compared to under non-mulching treatment. Losses in soil and nutrient are the main reasons of economic disadvantage. Economic loss due to soil loss was 45,610 won ha-1 for onion, 161,520 won ha-1 for sesame, and 46,740 won ha-1 for garlic if estimated soil value was 20,000 won ton-1. Nitrogen (N), phosphorus (P), and potassium (K) from runoff water was less observed under mulching treatments compared to non-mulching treatments. Overall, the contribution of economic loss for onion without mulching was 30% from soil loss and 70% from nutrient, while its loss with mulching was 42% from soil loss and 58% from nutrient. The contribution of economic loss for sesame without mulching was 90% from soil loss and 10% from nutrient, while its loss with mulching was 94% from soil loss and 6% from nutrient. For sesame current C factor without mulching was 0.34, while calculated C factor for sesame under mulching was 0.25. These results indicate that the amount of soil erosion and nutrient loss can be decreased under different crop management system. Especially, covering crops, such as mulching is important to reduce the amount of soil erosion if more frequent unexpected climate change events happen. Contribution of economical loss due to soil loss and nutrient loss under mulching and non-mulching treatment during onion, sesame, and garlic cultivation. Crop Total economical loss (Won) Contribution of economical loss (%) Mulching Mulching No Yes No Yes Soil loss Nutrient loss Soil loss Nutrient loss Onion 256,360 78,810 30 70 42 58 Sesame 281,300 98,710 90 10 94 6 Garlic 232,240 61,160 27 74 25 75