关键词: 土壤水分, 土壤水分, 自动, 人工, 对比分析, 明水

Abstract:

The effects of sowing depth and seed size on seedling establishment were focus issue at the seed science all the while. Soybean seed was tested in this paper by compare the seedling emergence percentage and seedling growth in the different sowing depth and seed size in the field. Seed of two varieties in soybean were divided artificially into three kinds of grain with big, middle and small size. These seed were sowed in depths of 5 cm, 10 cm and 15 cm in the field, respectively, and the seedling emergence time, percentage and main seedling characters were survey in the test. The results that the seedling emergence time was prolonged in the field, 6 d-13 d, 9 d-17 d and 13 d-23 d were needed by seedling emergence in 5 cm, 10 cm and 15 cm depth, respectively. Compared with indoor test, the final seedling emergence percentage in the field were decreased 7%, 34% and 80% in 5 cm, 10 cm and 15 cm depth, respectively. The seedling length and dry seedling weight were gradually reduced with sowing depth and shown a very significant difference (p < 0.01); Contrarily, root length was the longest in 15 cm depth and was the shortest in 5 cm depth. The dry root weight in 10 cm depth was heavy more than in 5 cm and 15 cm depth and shown significant difference (p < 0.05). Seedling growth was also affected by seed size. Both big and middle size was higher in seedling emergence percentage than small size with very significant difference (p < 0.01). The seedling length and dry weight gradually increased with seed size and shown significant difference (p < 0.05) among three seed size and vary significant difference (p < 0.01) between big and small size.