In general, available N, P, and K are the essential nutrients in soil for Chinese cabbage growth, and
the demand quantity of these nutrition elements is different at different growth stages[14]. When Chinese
cabbage was in the period of germination stage, the demand of nutrition was relatively less than that of
rosette stage. Combing to decomposition of celery waste and carnation stalk, the accumulation stage of
available N, P, and K would appear in the period of the germination stage to rosette stage. After the
rosette stage, the demand of nutrients will increase sharply and 90% available N, P, and K will be
absorbed during this stage[15]. As a result, their contents in the soil will decrease sharply. After heading
stage, the nutrients demand was decreased, therefore, the decrease trend of soil available N, P, and K content was slowed down.