Fertility status of guava orchards in Kohat District of Pakistan

摘要

A study was conducted to assess the fertility status of the soils of 44 guava orchards in Kohat District of Pakistan. Results showed that the soils generally contained large proportion of silt followed by sand with very small proportion of clay. Average organic matter content in the surface soil was 2.24% and in subsoil 1.42%. Soil pH ranged between 7.8 and 8.8. Soils at surface were non saline except one sample with EC ranging from 0.49 to 1.8 dS m-1?and in subsoil from 0.55 to 7.26 dS m-1. Soils were strongly calcareous with lime content ranging from 15 to 25%. Extractable P ranged from 1 to 22 mg kg-1?in both depths. Available K was between 103 and 393 mg kg-1, Nine, 16 and 43% of the orchards were low, 20, 18 and 48% marginal and 71, 66 and 9% were adequate in Zn, Fe and B in the surface soil while 7, 14 and 41% were low, 48, 27 and 52% marginal and 45, 59 and 7% of the orchards were adequate in Zn, Fe and B in the subsoil, respectively. Copper and Mn were adequate in all the orchards. Leaf P was low in 86% of the orchards.? Potassium was marginal in 16% and high in 84%. Eleven percent of the orchards were low in Zn, 16% in Cu, 50% in Fe, 16% in Mn and 9% in B. Orchards found deficiency in the nutrients should be fertilized in order to supply the needed nutrients.