Soil Nutrient Changes of Protected Land and Effect of Fertilizer on the Yield of Tomato in Harbin

With the increasing of using period of the protected land,the soil nutrient content of vegetable protected land in the city of Harbin has changed obviously.It is very important to study the changes of the protected land nutrient to increase the production of tomato.The study showed that soil nutrient content had improved greatly.The changes of soil nutrient content of different soil profile layers were significantly different in the recent protected lands,on the other hand,there were no significant differences among different soil profile layers of the former protected land.The situation of the soil nutrient had ameliorated and vegetable could grow better.Biologic organic fertilizer and inorganic fertilizer could promote the growth of tomato and increased the yield of tomato by 13.8%.