Effects of toposequence and soil loss on weed seed bank dynamics in upland maize production

Abstract

Weeds are the major pests in maize production and cause yield loss. Weed seed bank dynamic consists of input and output processes of weed distribution and composition. Some seeds of seed rain are able to remain as soil seed bank while some of which could be dispersed by erosion and runoff water, especially happening at high slope angles and elevation. This study aimed to determine the effects of toposequence and soil loss on soil seed bank dynamics through seed output by seed removal under natural rainfall and seed input by seed rain. Micro plots (1 m2) were installed on four slope positions (top, upper, middle, and down) in the upland maize production areas. Soil seed bank samples were collected using a soil core. Seed removal by natural rainfall was collected during rainy season in 2018. Seed rain was collected by seed traps for one year in 2019. The results showed that there were 95,095 seedlings/m2 for soil seed bank, 399 seedlings/m2 for seed loss, and 481,450 seeds/m2 for seed rain. A number of seed losses by natural rainfall and seeds of seed rain were accounted for seed output and seed input process, respectively. Seed rain contributed the greatest proportion in the input process of soil seed bank. Soil seed bank was affected by toposequence. Amount of soil seed bank was greatest at down slope position compared to other slope positions (p

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