Nutrition diagnosis and balanced application of fertilizers of Coffea arabica L. in coffee-litchi agroforestry

Under different applying amounts and rations of nitrogen(N),phosphorus(P),potassium(K) nutrients,the state of nutritions of Coffea arabica L.in coffee-litchi agroforestry was studied.It has been found that N is the most important factor of influencing the yield of C.arabica L.,and K and P are the next respectively.The yield can be improved obviously through spraying appropriate amount of B and Zn elements on the leaves.The ratio of the matching experiments in fertilization level of N,P,K is 1∶0.5∶1.Otherwise,the yield of C.arabica L.is increased with the increasing dosage of N,P,K,and the yield of fresh fruits is from 15 t/hm² to 30 t/hm².It has been suggested that the index of nutrition diagnosis of C.arabica L.in Simao region is 25～30gN/kg,1.0～1.5gP/kg,15～25gK/kg,10～12gCa/kg,2.5～5.0gMg/kg,10～15mgZn/kg and 40～50mgB/kg.The most optimum amounts of fertilizers of N,P₂O₅,K₂O are 50～100g,25～50g,50～100g for a plant in one year respectively.