Abstract:

Through the project of soil testing and fertilizer recommendation from Ministry of Agriculture, a lot of data about soil fertility were acquired. Based on the data obtained in 2009 and 2010, current situation of the soil fertilities in tobaccogrowing regions in Hubei province were systematic analyzed. Tabacco growing areas were divided into four regions, I. surrouding Shennongjia, mainly including Shiyan; II. the southwest of Hubei around Enshi; III. Shennongjia region; IV. the northwest of Hubei mainly including Xiangyang and Yichang. The purpose of research is to clarify soil nutrient abundant and deficient status in different tobaccogrowing regions and soil types in Hubei province. Results indicated that presently tobaccogrowing soil in Hubei province were 62 on average in pH, 233 g/kg on average in organic matter, 1097 mg/kg on average in alkalystic N, 195 mg/kg on average in available P and 1236 mg/kg on average in available K, respectively. The pH of 569% soil was in range of 50-70 which was suitable for tobacco growth. In addition, the concentrations of soil organic matter of 617% samples were in range of 15-35 g/kg. Among all the soil samples, 481 percent showed alkalystic N less than 100 mg/kg, 363 percent of soils showed available P less than 10 mg/kg and 574 percent showed available K less than 120 mg/kg, and they were at deficient level in alkalystic N, available P or available K. The soil nutrients varied to a varying extent from region to region. Soil pH on average was the lowest in the southwest of Hubei around Enshi and highest in surronding Shennongjia and Shennongjia regions. Soil organic matter was significantly higher in the southwest of Hubei and Shennongjia regions than surrounding Shennongjia and the northwest of Hubei. Soil alkalystic N and available P in the southwest of Hubei averaged 1369 mg/kg and 230 mg/kg, respectively, 〖JP2〗that were obviously higher than in other three regions. Soil available K was just opposite, that in I to IV regions were 1240 mg/kg, 1167 mg/kg, 1339 mg/kg and 1290 mg/kg on average, respectively. It means that available K of soil in the southwest of Hubei was the lowest among these four tobaccogrowing regions. Main soil types of tobaccogrowing areas in Hubei province were yellow brown soil, paddy soil, yellow soil, limy soil, purple soil and brown soil. The six soil types represent more than 90 percent of tobaccogrowing soil in Hubei province. Because of different conditions and soil forming parent materials, the soil nutrients contents in different soil types were significant difference. The results also revealed that soil fertility of brown soil was higher than other five soil types with 343 g/kg on average in soil organic matter, 1403 mg/kg on average in alkalystic N, 256 mg/kg on average in available P and 1751 mg/kg on average in available K, respectively. The average value of soil organic matter and alkalystic N in purple soil were lowest with 175 g/kg and 963 mg/kg. Available P and available K of soil in paddy soil were 176 mg/kg and 1012 mg/kg on average, which is the lowest value among the six soil types. The study aslo showed that by making full use of the data of the project of soil testing and fertilizer recommendation and conducting systematic analysis of the soil nutrient data, it is feasible to obtain the status quo of soil fertility of a region and provide a scientific and reasonable guidance for fertilization.