The results showed that the dry matter and NPK accumulation of cucumber were “S” curve.

Study on Balanced Application of NPK Fertilizer on Growth of Paeonia lactiflora with Orthogonal Design;

NPK fertilizer response and optimum application rate for winter potatoes;

Fertilizer Response and Optimum Application Rate of NPK on Sweet Potato;

In N-P-K fertilizer efficiency experiment with part implementing plan of "3414",5 treatments of non-fertilizer plot(CK),non-nitrogen plot(applying P and K fertilizer),non-phosphorus plot(applying N and K fertilizer),non-potassium plot(applying N and P fertilizer) and entire fertilizer plot(applying N,P and K fertilizer)were set up.

The effects of different N-P-K levels on agronomic traits and nutrient contents of southern autumn maize were studied in a L4(23)orthogonal experiment with 4 treatments: no fertilizer(CK),no potassium(with P and N),no phosphorus(with N and K) and no nitrogen(with P and K).

The result indicated that N had the most effect on the yield of hot cluster red pepper in NPK and there was obvious interaction between N and P.

By means of orthogonal tyrotational combination design,a three-factor(NPK)substrate cultivation experiment was conducted on N P K content for soilless culture of Malus domestica Winter Red Fruit ,and the regressive equation was estab- lishad between the application level of N P K and chlorophyll content in leaf and anthocyanin content in fruit.