5Alva A K, Paramasivam S. Nitrogen management for high yield and quality of citrus in sandy soils[J]. Soil Sci. Soc. Am. J, 1998, 62:1335-1342.
6Alva A K, Paramasivam S, Graham W D. Best nitrogen and irrigation management practices for citrus production in sandy soils[J]. Water,Air, and Soil Pollution, 2003, 143: 139-154.
7Dou H, Alva A K. Nitrogen uptake and growth of two citrus rootstock seedlings in a sandy soil receiving different controlled-release fertilizer sources[J]. Biol. Fert. Soils, 1998, 26: 169-172.
8Cantarella H, Mattos Jr D, Quaggio J A et al. Fruit yield of Valencia sweet orange fertilized with different N sources and the loss of applied N[J]. Nutrient Cycling in Agroecosystems, 2003, 67: 215-223.
10Quaggio J A, Cantarella H, Raij van B. Phosphorus and potassium soil test and nitrogen leaf analysis as a base for citrus fertilization[J]. Nutrient Cycling in Agroecosystems, 1998, 52: 67-74.
