China has to raise agricultural productivity in its limited and shrinking farmland to guarantee food security for its huge and ever-growing population. Sustainable soil nutrient management is of paramount importance t...China has to raise agricultural productivity in its limited and shrinking farmland to guarantee food security for its huge and ever-growing population. Sustainable soil nutrient management is of paramount importance to the world's most populous country. Critical challenges the country is facing in sustaining soil fertility and in alleviating the hazardous impact of intensive fertilizer use are discussed in this paper. It is emphatically pointed out that national strategies as well as area-specific action plans with respect to scientific nutrient management are urgently needed to balance productivity and sustainability in the future. Relevant proposals for addressing those challenges are also presented.展开更多
The mineral fertilizers (NPK) and pesticide, including herbicides, insecticides and fungicides, were applied alone or in combination and the soil sampling was done at different growth stages during the crop cycle to s...The mineral fertilizers (NPK) and pesticide, including herbicides, insecticides and fungicides, were applied alone or in combination and the soil sampling was done at different growth stages during the crop cycle to study the changes in soil organic matter, microbial biomass and their activity parameters in a paddy soil with different nutrient and pest management practices in a hybrid rice double-cropping system. A consistent increase in the electron transport system (ETS) activity was measured during the different crop growth stages of rice. The use of fertilizers (NPK) alone or with pesticides increased ETS activity, while a decline of ETS activity was noticed with pesticides alone as compared with the control. Nearly an increasing trend in soil phenol content was observed with the progression of crop growth stages, while the usage of pesticides alone caused maximum increments in the soil phenol content. The soil protein content was found nearly stable with fertilizers and/or pesticides application at various growth stages in both crops taken. But notable changes were noticed at different growth stages probably because of fluctuations in moisture and temperature at particular stages, which might have their effects on N mineralization. Marked depletions in the phospholipid content were found with the advancement of crop growth stages, while the incorporation of fertilizers and/or pesticides also produced slight changes, in which a higher decline was noticed with pesticide application alone compared with the control.展开更多
This study aimed to first assess knowledge levels of the farmers in the use of manure, fertilizer and combinations of manure and fertilizer and secondly to identify the socioeconomic factors influencing the levels of ...This study aimed to first assess knowledge levels of the farmers in the use of manure, fertilizer and combinations of manure and fertilizer and secondly to identify the socioeconomic factors influencing the levels of knowledge in the use of animal manure, inorganic fertilizers and combination of animal manure and inorganic fertilizers in Meru South, Maara and Mbeere South districts of the central highlands of Kenya. Data were collected from a random sample of 300 households through face to face interviews using an interview schedule. The data was analyzed using descriptive statistics and binary logistic regression model. Results showed that 75% and 73% of the respondents had high levels of knowledge in use of manure and fertilizers, respectively, while 43% of the respondents had moderate levels of knowledge in the use of manure ＋ fertilizers. Age of the household head （HHH） training in the use of animal manure and group membership significantly influenced household levels of knowledge in use of animal manure. In regard to levels of knowledge on fertilizer use, group membership, age of the HHH and total farm size were important explanatory variables while gender of the HHH, household size, training on manure ＋ fertilizers, group membership and total farm size were important in influencing the levels of knowledge in use of manure ＋ fertilizers. The implication of these results is that training and belonging to a group enhances level of knowledge on soil fertility management and development, so workers should focus on these two aspects.展开更多
基金Project supported by the Knowledge Innovation Program of Chinese Academy of Sciences (Nos. KZCX3-SW-417 and KZCX2-413).
文摘China has to raise agricultural productivity in its limited and shrinking farmland to guarantee food security for its huge and ever-growing population. Sustainable soil nutrient management is of paramount importance to the world's most populous country. Critical challenges the country is facing in sustaining soil fertility and in alleviating the hazardous impact of intensive fertilizer use are discussed in this paper. It is emphatically pointed out that national strategies as well as area-specific action plans with respect to scientific nutrient management are urgently needed to balance productivity and sustainability in the future. Relevant proposals for addressing those challenges are also presented.
基金Project supported by the National Natural Science Foundation of China (No. 39970146) the Interna- tional Rice Research Institute (IRRI) under project of Reversing Trends of Declining Productivity (RTDP).
文摘The mineral fertilizers (NPK) and pesticide, including herbicides, insecticides and fungicides, were applied alone or in combination and the soil sampling was done at different growth stages during the crop cycle to study the changes in soil organic matter, microbial biomass and their activity parameters in a paddy soil with different nutrient and pest management practices in a hybrid rice double-cropping system. A consistent increase in the electron transport system (ETS) activity was measured during the different crop growth stages of rice. The use of fertilizers (NPK) alone or with pesticides increased ETS activity, while a decline of ETS activity was noticed with pesticides alone as compared with the control. Nearly an increasing trend in soil phenol content was observed with the progression of crop growth stages, while the usage of pesticides alone caused maximum increments in the soil phenol content. The soil protein content was found nearly stable with fertilizers and/or pesticides application at various growth stages in both crops taken. But notable changes were noticed at different growth stages probably because of fluctuations in moisture and temperature at particular stages, which might have their effects on N mineralization. Marked depletions in the phospholipid content were found with the advancement of crop growth stages, while the incorporation of fertilizers and/or pesticides also produced slight changes, in which a higher decline was noticed with pesticide application alone compared with the control.
文摘This study aimed to first assess knowledge levels of the farmers in the use of manure, fertilizer and combinations of manure and fertilizer and secondly to identify the socioeconomic factors influencing the levels of knowledge in the use of animal manure, inorganic fertilizers and combination of animal manure and inorganic fertilizers in Meru South, Maara and Mbeere South districts of the central highlands of Kenya. Data were collected from a random sample of 300 households through face to face interviews using an interview schedule. The data was analyzed using descriptive statistics and binary logistic regression model. Results showed that 75% and 73% of the respondents had high levels of knowledge in use of manure and fertilizers, respectively, while 43% of the respondents had moderate levels of knowledge in the use of manure ＋ fertilizers. Age of the household head （HHH） training in the use of animal manure and group membership significantly influenced household levels of knowledge in use of animal manure. In regard to levels of knowledge on fertilizer use, group membership, age of the HHH and total farm size were important explanatory variables while gender of the HHH, household size, training on manure ＋ fertilizers, group membership and total farm size were important in influencing the levels of knowledge in use of manure ＋ fertilizers. The implication of these results is that training and belonging to a group enhances level of knowledge on soil fertility management and development, so workers should focus on these two aspects.
