Agricultural activities that encourage slashing, burning and ploughing greatly affect the soil structure and soil organic matter on which soil water retention depends. In this study, we hypothesized that inclusion of ...Agricultural activities that encourage slashing, burning and ploughing greatly affect the soil structure and soil organic matter on which soil water retention depends. In this study, we hypothesized that inclusion of rotational leguminous tree species improves soil water retention in a semi-arid conservation agriculture system. In a study done in Kibwezi, semi-arid eastern Kenya, results showed that the amount of water retained in the different soil strata from plots with different tree species and tillage practices was highly significant (P = 0.032). Plots with planting basins and Gliricidia sepium and Faidherbia albida tree species retained more water in both the upper and lower strata. Plots with G. sepium tree species under planting basins and zero tillage under F. albida had significantly higher soil organic carbon levels than plots that were managed under ridges and ploughing (P = 0.002). On the other hand, bulk density in plots with planting basins and zero tillage and ridges ranged between 1.35 g/cm3 and 1.53 g/cm3. Conventional tillage plots had bulk density values of 1.65 g/cm3 and 1.72 g/cm3 in the upper and lower strata respectively. The time-dependent nature of rotational leguminous tree species on soil organic matter and soil water retention in the semi-arid conservation agriculture system highlights the importance of considering these species for improving organic carbon and water retention for improved crop production.展开更多
In this paper, we introduce some new classes of the totally quasi-G-asymptotically nonexpansive mappings and the totally quasi-G-asymptotically nonexpansive semigroups. Then, with the generalized f-projection operator...In this paper, we introduce some new classes of the totally quasi-G-asymptotically nonexpansive mappings and the totally quasi-G-asymptotically nonexpansive semigroups. Then, with the generalized f-projection operator, we prove some strong convergence theorems of a new modified Halpern type hybrid iterative algorithm for the totally quasi-G-asymptotically nonexpansive semigroups in Banach space. The results presented in this paper extend and improve some corresponding ones by many others.展开更多
In this study, beetle communities in Jiuzhaigou, Xiaozhaizigou, Caopo, Ma＇anshan and Baihe nature reserves of Sichuan Province were compared and analyzed. F index, G index and G-F index of beetle communities in five ...In this study, beetle communities in Jiuzhaigou, Xiaozhaizigou, Caopo, Ma＇anshan and Baihe nature reserves of Sichuan Province were compared and analyzed. F index, G index and G-F index of beetle communities in five nature reserves were analyzed to calculate the similarity coefficient C between these five na- ture reserves. According to the results, beetle communities exhibited high dissimilarity between Jiuzhaigou and Xiaozhaizigou, Caopo and Jiuzhaigou, Caopo and Xiaozhaizigou, Ma＇anshan and Xiaozhaizigou, Ma＇anshan and Jiuzhaigou, Baihe and Xiaozhaizigou, Baihe and Caopo, Baihe and Ma＇anshan; beetle communities exhibited moderate dissimilarity between Ma＇anshan and Caopo, Baihe and Jiuzhaigou.展开更多
文摘Agricultural activities that encourage slashing, burning and ploughing greatly affect the soil structure and soil organic matter on which soil water retention depends. In this study, we hypothesized that inclusion of rotational leguminous tree species improves soil water retention in a semi-arid conservation agriculture system. In a study done in Kibwezi, semi-arid eastern Kenya, results showed that the amount of water retained in the different soil strata from plots with different tree species and tillage practices was highly significant (P = 0.032). Plots with planting basins and Gliricidia sepium and Faidherbia albida tree species retained more water in both the upper and lower strata. Plots with G. sepium tree species under planting basins and zero tillage under F. albida had significantly higher soil organic carbon levels than plots that were managed under ridges and ploughing (P = 0.002). On the other hand, bulk density in plots with planting basins and zero tillage and ridges ranged between 1.35 g/cm3 and 1.53 g/cm3. Conventional tillage plots had bulk density values of 1.65 g/cm3 and 1.72 g/cm3 in the upper and lower strata respectively. The time-dependent nature of rotational leguminous tree species on soil organic matter and soil water retention in the semi-arid conservation agriculture system highlights the importance of considering these species for improving organic carbon and water retention for improved crop production.
文摘In this paper, we introduce some new classes of the totally quasi-G-asymptotically nonexpansive mappings and the totally quasi-G-asymptotically nonexpansive semigroups. Then, with the generalized f-projection operator, we prove some strong convergence theorems of a new modified Halpern type hybrid iterative algorithm for the totally quasi-G-asymptotically nonexpansive semigroups in Banach space. The results presented in this paper extend and improve some corresponding ones by many others.
基金Supported by Key Project of Sichuan Provincial Department of Education(07ZA122)
文摘In this study, beetle communities in Jiuzhaigou, Xiaozhaizigou, Caopo, Ma＇anshan and Baihe nature reserves of Sichuan Province were compared and analyzed. F index, G index and G-F index of beetle communities in five nature reserves were analyzed to calculate the similarity coefficient C between these five na- ture reserves. According to the results, beetle communities exhibited high dissimilarity between Jiuzhaigou and Xiaozhaizigou, Caopo and Jiuzhaigou, Caopo and Xiaozhaizigou, Ma＇anshan and Xiaozhaizigou, Ma＇anshan and Jiuzhaigou, Baihe and Xiaozhaizigou, Baihe and Caopo, Baihe and Ma＇anshan; beetle communities exhibited moderate dissimilarity between Ma＇anshan and Caopo, Baihe and Jiuzhaigou.
