Diversity and Population of Weeds Propagules in Soybean at Various Soil Depths

Abstract Weeds can cause losses in soybean crops of up to 80%. Weed propagules influence weed population and diversity in the soil. This research aims to obtain the diversity and population of weed propagules in soybean fields with various soil depths. This research was conducted using surveys and interviews in soybean fields in Dlingo District, Bantul Regency, Special Region of Yogyakarta. The survey method was carried out by taking samples of weeds and soil in three plots of soybean land with a depth of 0 cm, 10 cm, 20 cm, and 30 cm using quadrats in three observation plots measuring 30 cm × 30 cm as well as an interview method to find out how soybean cultivation is carried out. Weed samples and soil samples were collected three weeks after planting (vegetative phase), six weeks after planting (flowering), nine weeks after planting (pod formation), and 11 weeks after planting (ripe pods), so there were 36 sample points in one shot in one phase. The results showed that weed propagules in soybean fields at a 0-10 cm soil depth had higher diversity than at a 20-30 cm soil depth. The weeds that dominate soybean plantations are Portulaca oleracea, Euphorbia prostrata, Oldenlandia corymbosa , and Cleome rutidosperma . Soil depth influences the population of weed propagules in soybean plantations. A soil depth of 0 cm has the highest population of weed propagules, and the population decreases in deeper soil. The results of this research can be used as a reference in determining appropriate methods of controlling weed propagules in soybean fields. The results of this research can be used as a reference in deciding appropriate weed control methods for weed conditions in soybean fields