The suitable soil moisture of watermelon is 65%-78% of the maximum water holding capacity in the field , and the drought is like the soil moisture below 48% . The requirement of soil moisture in watermelon is high germination period, less seedling period, moderate amount of vines, and the middle stage is the peak period of water demand. It should be fully irrigated, and in the later stage, irrigation should be reduced.

 

The fertilization of watermelon should be based on the application of the base fertilizer, and the topdressing should be carried out. In the fruit expansion period , 3 kg of potassium sulfate and 30 kg of diammonium per acre are applied . Before and after the setting of the melon, it is possible to spray a mixture of 0.2% urea and 0.2% potassium dihydrogen phosphate on the foliar surface . Observe whether the watermelon is lack of fertilizer, depending on the color of the leaves, if the base leaves are dark green, the middle leaves are green, and the top leaves are light green, indicating normal growth; if the whole plant is yellow-green from top to bottom, it indicates lack of fertilizer; if the leaves are plant From top to bottom, it is dark green, indicating that there is too much nitrogen fertilizer, it will take a long time, and it needs to be controlled.