ELECTRICAL CONDUCTIVITY AND PH OF ROOT ZONE SOIL AS AFFECTED BY CONTINUOUS AND COMBINED APPLICATION OF CHEMICAL FERTILIZERS TO CUCUMBER CULTURED IN SOLAR GREENHOUSES

Five chemical fertilizers (urea, ammonium sulphate, ammonium diphosphate, potash sulphate and calcium monophosphate) combined in different kinds and NPK ratios were continuously applied to potted cucumber (Cucumis sativus L.) in a solar greenhouse to study their effects on electrical conductivity and pH of root zone soil.
The results revealed that: continuous cropping increased soil salinity and decreased pH, and gradually enhanced the treatment effects among different fertilizer combinations; increase of nitrogen rate gradually raised the electrical conductivity of soil, especially when using ammonium sulphate as nitrogen source; adding more amount of phosphorus or potassium significantly accelerated the electrical conductivity to rise after several continuous crops; a large amount of nitrogen markedly decreased soil pH value, particularly using ammonium sulphate as nitrogen source and under the conditions of multiple cropping, while adding the rate of phosphorus or potassium less affected the soil pH value.

XXVII International Horticultural Congress – IHC2006: International Symposium on Advances in Environmental Control, Automation and Cultivation Systems for Sustainable, High-Quality Crop Production under Protected Cultivation

M. Wei, T.L. Li, H. Xu, X.F. Wang, Y.D. Yin

urea, ammonium sulphate, ammonium diphosphate, potash sulphate, calcium monophosphate, continuous cropping, NPK ratio

https://doi.org/10.17660/ActaHortic.2007.761.63