Effect of fertilization amount and ratio on yield, quality and nutrient absorption of watermelon

The aim of this study was to determine optimum fertilization amount and ratio for sustainable product of watermelon. To that end, field experiments were conducted, and the watermelon yield, quality and nutrient absorption rate under different fertilization treatments were investigated. Results indicate that yield and Vc content of watermelon under DNPK (decreased nitrogen, phosphorus and potassium) treatment respectively increase by 0.77% and 17.18% over TF (traditional fertilization) method. Sugar and nitrate contents under DNPK treatment respectively decrease by 12.56% and 27.94% over TF treatment. Yield, and Vc and sugar content of watermelon under DNPIK (decreased nitrogen, phosphorus and increased potassium) treatment are higher than under either DNP (decreased nitrogen and phosphorus) or DNPK treatment. Nitrate content under DNPIK treatment is lower than that under either DNP or DNPK treatment. N︰P₂O₅︰K₂O ratio in watermelon stem under TF, DNPK, DNP and DNPIK treatments are respectively 1︰0.18︰2.26, 1︰0.22︰2.66, 1︰0.26︰2.75, and 1︰0.19︰2.46. The ratio of N︰P₂O₅︰K₂O in watermelon peel under TF, DNPK, DNP and DNPIK treatments are respectively 1︰0.34︰2.78, 1︰0.34︰2.60, 1︰0.30︰2.37 and1︰0.29︰2.14. Given the above facts, watermelon average fertilization amount could be less by 36% than that of TF, with N︰P₂O₅︰K₂O ratio of 1︰0.41︰1.28, being the best fertilization of watermelon.