Nutrient Management for Cucumber

A field experiment was carried out to test the response of cucumber to macro- and secondary-nutrients in well-managed vegetable fields in Penzhou City, Sichuan Province. The experiment consisted of seven treatments, including the optimal treatment (OPT, 270-120-360 kg N-P₂O₅-K₂O/ha), OPT-N, OPT-P, OPT-K, OPT+1/2K, OPT-1/2K, and OPT+CaMg (750 kg Ca(OH)₂+300 kg MgSO₄/ha). Nitrogen was used as urea (46% N), P as SSP (12% P₂O₅) and K as KCl (60% K₂O). All P, lime and MgSO₄, 50% of N and 50% of K were applied as basal fertilizers at seedling transplanting. The remaining N and K fertilizers were topdressed at flowering and fruit harvest stages.

The OPT treatment produced 1.58 (2%), 0.66 (1%) and 10.28 (14%) t/ha more cucumber yields than the treatments omitting N, P or K, respectively. Thus, even in this well-managed vegetable base, K is still the number one nutrient limiting factor. Compared to the OPT, the OPT-1/2K treatment reduced cucumber yield by 8.2% and OPT+1/2 K treatment increased cucumber yield by 2.1%. Since the yield increases due to addition of N and P were quite small, N and P rates should be readjusted to lower levels in future studies. The OPT+CaMg treatment significantly increased cucumber yield by an additional 6.4 t/ha (8.9%) and also improved cucumber quality (enhanced vitamin C, amino acids, and lower nitrate contents in the fruit) indicating the importance of these two secondary nutrients in cucumber production in this vegetable area.