Effect of N P and K fertilizers on rice yields at several regions in Indonesia

Fertilization using P and K without N failed to increase rice yields in Grobogan, while N significantly increased the harvested dry grain weight, milled dry grain weight, and dry straw weight. The highest weight of harvested dry grain and milled dry grain weight was achieved with 180 kg N ha-1 dose, while the highest dry straw weight was 135 kg N ha-1.Meanwhile, in Pandeglang, West Java Province, the tallest rice crop was achieved with 180 kg N ha-1 dose. Fertilization significantly augmented rice yields obtained from fields in Pandeglang, while the supply of P and K alone without N did not trigger any increase. The application of a 90 kg N ha-1 dose significantly increased rice yield compared to the control.In Sukadana, Lampung Province, N, P, and K fertilization significantly increased yields in rice fields, but providing P and K only to the plants without N addition did not lead to yield elevation in harvested dry weight, milled dry weight, and dry straw weight. N fertilization with a 90 kg ha-1 dose significantly increased rice yields compared to the control. Providing 180 kg ha-1 of N fertilizer did not elevate the harvested dry grain weight compared to 90 kg ha-1 of N fertilizer.The effect of NPK fertilization on the weight of harvested dry grain and milled dry grain in rice fields in Grobogan, Pandeglang, and Sukadana are presented in figure 3.