The composition of major nutrients, i.e. nitrogen, phosphorus and potassium (NPK), is a critical factor in banana cultivation and also influences crop yield. This study was aimed to analyze the concentrations of NPK i...The composition of major nutrients, i.e. nitrogen, phosphorus and potassium (NPK), is a critical factor in banana cultivation and also influences crop yield. This study was aimed to analyze the concentrations of NPK in different banana growing locations of coastal areas of Sindh, Pakistan. A total of 15 composite soil samples at the depth of 0 - 15 and 15 - 30 cm and the same number of banana leaves were collected. The samples were analyzed for the concentration of N, P, K, Ca, Mg, Zn, Mn and Cl concentrations. Results showed that the surface and sub-surface soils of coastal areas were heavy in texture, non-saline, medium alkaline and moderately calcareous in nature. Medium to adequate in Organic Matter (OM), medium in total nitrogen, medium to optimum in available phosphorus, medium to high in exchangeable potassium and deficient in available zinc at both tested depths. The analysis of soluble anions indicated that the carbonates were absent and that chlorides were dominant as compared with bicarbonates. Nitrogen and zinc concentrations of banana leaves were below the critical level, whereas P, K, Mn and chloride ion concentration were above the critical levels. In addition, the relative percentages for K, Ca and Mg were 57.72 to 61.72, 19.05 to 21.00 and 17.70 to 20.00 respectively.展开更多
Soil hydraulic properties were mainly governed by soil structures especially when the structures is full of the connected soil macro-pores.Therefore,the good hydrological models need to be well documented for revealin...Soil hydraulic properties were mainly governed by soil structures especially when the structures is full of the connected soil macro-pores.Therefore,the good hydrological models need to be well documented for revealing the process of soil water movement affected by soil medium.The Hydrus-2D model with double domain was recommended in simulating water movement in a heterogeneous medium of soil.To evaluate the performance of the double domain Hydrus-2D model in loess soil,the dynamic of soil wetting front movement in differential loess soil columns under the constant water head were observed and the processes was simulated by Hydrus-2D model under conditions of different soil properties.The results indicated that the Hydrus-2D model was quite good in simulation of loess soil water movements,and the relative errors of simulation results are less than 15%,MRE less than 5%,and R^(2)>0.9.The results provided the appropriate infiltration parameters of loess soil.展开更多
文摘The composition of major nutrients, i.e. nitrogen, phosphorus and potassium (NPK), is a critical factor in banana cultivation and also influences crop yield. This study was aimed to analyze the concentrations of NPK in different banana growing locations of coastal areas of Sindh, Pakistan. A total of 15 composite soil samples at the depth of 0 - 15 and 15 - 30 cm and the same number of banana leaves were collected. The samples were analyzed for the concentration of N, P, K, Ca, Mg, Zn, Mn and Cl concentrations. Results showed that the surface and sub-surface soils of coastal areas were heavy in texture, non-saline, medium alkaline and moderately calcareous in nature. Medium to adequate in Organic Matter (OM), medium in total nitrogen, medium to optimum in available phosphorus, medium to high in exchangeable potassium and deficient in available zinc at both tested depths. The analysis of soluble anions indicated that the carbonates were absent and that chlorides were dominant as compared with bicarbonates. Nitrogen and zinc concentrations of banana leaves were below the critical level, whereas P, K, Mn and chloride ion concentration were above the critical levels. In addition, the relative percentages for K, Ca and Mg were 57.72 to 61.72, 19.05 to 21.00 and 17.70 to 20.00 respectively.
基金This study was funded by the National Natural Science Foundation of China(41471439,41171421)Chinese Academy of Sciences Visiting Professorships for Senior International Scientists(serial number:2013T2Z0027).
文摘Soil hydraulic properties were mainly governed by soil structures especially when the structures is full of the connected soil macro-pores.Therefore,the good hydrological models need to be well documented for revealing the process of soil water movement affected by soil medium.The Hydrus-2D model with double domain was recommended in simulating water movement in a heterogeneous medium of soil.To evaluate the performance of the double domain Hydrus-2D model in loess soil,the dynamic of soil wetting front movement in differential loess soil columns under the constant water head were observed and the processes was simulated by Hydrus-2D model under conditions of different soil properties.The results indicated that the Hydrus-2D model was quite good in simulation of loess soil water movements,and the relative errors of simulation results are less than 15%,MRE less than 5%,and R^(2)>0.9.The results provided the appropriate infiltration parameters of loess soil.
