Reducing Chemical Fertilizer Application in Greenhouse Vegetable Cultivation under Different Residual Levels of Nutrient

Excessive chemical fertilizer application in greenhouse vegetable cultivation results environmental risks and residual nutrients the soil. Conventional plot experiments conducted one field cannot recommend reduction to farmers when nutrient levels were various among different fields. In this study, nine simultaneously fields where soils could reflect of nutrient, with two rates (100 0%) for each nitrogen, phosphorus, potassium fertilizer. The showed that did not decrease yield soil nitrate, Olsen–phosphorus, exchangeable ≥173.3, 45.8, 93.1 mg kg−1, respectively. However, no N treatment decreased yields 1–3 because inadequately nitrate (≤103.9 kg−1) these led low absorbed from sources other than fertilizer, high recovery efficiencies N, productivity Residual EC was limiting factor under reduction. This study indicated reducing should be based on level soil, which is meaningful agricultural sustainability safety.