Abstract:

In order to better realize status and variation trend of principal soil nutrients of state-level modern tobacco agriculture base units in Lichuan, and guide the soil conservation and tobacco balanced fertilization, soil survey analysis and fixed-point investigation analysis have been developed divided into two years. The results showed that average pH values in soil of both Baiyang and Wangying base units were tending to decline, but the changes were different; the former has been moving toward optimum interval for tobacco growth, and the latter trends evident toward further acidified. The contents of alkali-hydrolyzable nitrogen and organic matter of both base units were close to medium level, and the Baiyang base unit showed a drop tendency while the Wangying base unit was just on the contrary. Available phosphorus values of both base units were at medium level, and the former declined clear while the latter increased clear. The contents of available potassium of both base units were increased by some extent, but soil K deficiency was still over 50%. Difference between regional distributions of the content tended to increase. According to status and variation trend of principal soil nutrients, the change causes of soil nutrient indexes have been analyzed combined with the actual production condition in this area. The relationships of available phosphorus and other nutrient indexes have been investigated, and some suggestions to soil improvement were put forward.