A field experiment was carried out to study nutrient balance among N, P, K and Mg in potato cultivation on an acid purple soil in Chongqing, China. The experiment included 8 treatments with equal P rate of 120 kg P2O5...A field experiment was carried out to study nutrient balance among N, P, K and Mg in potato cultivation on an acid purple soil in Chongqing, China. The experiment included 8 treatments with equal P rate of 120 kg P2O5 hm-2: N0K2, N1K2, N2K2, N3K2, N2K0, N2K1, N2K1Mg and N2K3, where N0, N1, N2 and N3 stand for the N rates of 0, 75, 150 and 225 kg N hm-2, and K0, K1, K2 and K3 for the K rates of 0, 165, 330 and 495 kg K2O hm-2, respectively. Among the treatments designed, Thatment N2K2 with a nutrient supply ratio of N:P2O5:K2O:MgO = 1.25:1:2.75:0.28 gave the highest tuber yield and dry matter, highest starch and Zn and lowest NO3- contents in tuber, and high N, P and K use efficiency with an uptake ratio of N:P:K:Mg = 11.38:1:13.32:0.33 by tuber. Yield and starch and protein contents of tuber were the lowest in Treatment N0K2. Dry matter was the lowest but protein and NO3- contents were the highest in Treatment N2K0. Treatment N2K1Mg had the highest N, P and K utilization rates. Statistical analysis showed that yields of tuber and starch were in a positive linear correlation with the uptake amount of various nutrients and protein of the potato tuber was in a significantly positive linear correlation with tuber N cotent and in a significantly negative linear correlation with tuber K and Mg contents. Balanced application of N, P, K and Mg fertilizers (Treatmeat N2K2) was recommended for realization of high yield and good quality in potato cultivation.展开更多
The ＂Silk Road Economic Belt＂ and the ＂China Dream＂ are tightly linked together rather than isolated from each other. The essence of the construction of the ＂Silk Road Economic Belt＂ is to give equal considerati...The ＂Silk Road Economic Belt＂ and the ＂China Dream＂ are tightly linked together rather than isolated from each other. The essence of the construction of the ＂Silk Road Economic Belt＂ is to give equal considerations to both the East and the West, paying equal attentions to the North and the South, while balancing the land and the sea and connecting domestic with foreign. This is the innovation and priority of China＇s peripheral diplomacy as well as a strategic support and tactical guarantee of the ＂China Dream＂. The ＂Silk Road Economic Belt＂ is constructed to make history serve reality; it exchanges economy for politics, space on land for time at sea, and balances a weakness in sea power with superiority in land power. Instead of simply replicating the Silk Road, the ＂Silk Road Economic Belt＂ possesses a broader realm and a richer context. Moreover, this is China＇s ultimate strategy and profound tactical conception facing toward the future.展开更多
Overuse of fertilizers and the resultant pollution and eutrophication of surface and groundwater is a growing issue in China. Consequently, improved management strategies are needed to optimize crop production with re...Overuse of fertilizers and the resultant pollution and eutrophication of surface and groundwater is a growing issue in China. Consequently, improved management strategies are needed to optimize crop production with reduced nutrient inputs. Conventional fertilization （CF）, reduced fertilization （RF）, and reduced fertilization with maize （Zea mays L.） as a summer catch crop （RF＋C） treatments were evaluated in 2008 and 2009 by quantifying tomato （Lycopersieon esculentum） fruit yield and soil nutrient balance in a greenhouse tomato double-cropping system. Fertilizer nitrogen （N） application was reduced by 37% in the RF and RF＋C treatments compared to the CF treatment with no significant reduction in fruit yield. Mean soil mineral N （Nmin） content to a depth of 180 cm following tomato and maize harvest was lower in the RF and RF＋C treatments than in the CF treatment. Residual soil Nmin content was reduced by 21% and 55% in the RF and RF＋C treatments, respectively, compared to the CF treatment. Surplus phosphorus （P） and potassium （K） contents in the RFWC treatment were significantly lower than those in the RF treatment, mainly due to additional P and K uptake by the catch crop. We concluded that for intensive greenhouse production systems, the RF and RF＋C treatments could maintain tomato fruit yield, reduce the potential for nitrate （NO3^--N） leaching, and with a catch crop, provide additional benefits through increased biomass production.展开更多
文摘A field experiment was carried out to study nutrient balance among N, P, K and Mg in potato cultivation on an acid purple soil in Chongqing, China. The experiment included 8 treatments with equal P rate of 120 kg P2O5 hm-2: N0K2, N1K2, N2K2, N3K2, N2K0, N2K1, N2K1Mg and N2K3, where N0, N1, N2 and N3 stand for the N rates of 0, 75, 150 and 225 kg N hm-2, and K0, K1, K2 and K3 for the K rates of 0, 165, 330 and 495 kg K2O hm-2, respectively. Among the treatments designed, Thatment N2K2 with a nutrient supply ratio of N:P2O5:K2O:MgO = 1.25:1:2.75:0.28 gave the highest tuber yield and dry matter, highest starch and Zn and lowest NO3- contents in tuber, and high N, P and K use efficiency with an uptake ratio of N:P:K:Mg = 11.38:1:13.32:0.33 by tuber. Yield and starch and protein contents of tuber were the lowest in Treatment N0K2. Dry matter was the lowest but protein and NO3- contents were the highest in Treatment N2K0. Treatment N2K1Mg had the highest N, P and K utilization rates. Statistical analysis showed that yields of tuber and starch were in a positive linear correlation with the uptake amount of various nutrients and protein of the potato tuber was in a significantly positive linear correlation with tuber N cotent and in a significantly negative linear correlation with tuber K and Mg contents. Balanced application of N, P, K and Mg fertilizers (Treatmeat N2K2) was recommended for realization of high yield and good quality in potato cultivation.
文摘The ＂Silk Road Economic Belt＂ and the ＂China Dream＂ are tightly linked together rather than isolated from each other. The essence of the construction of the ＂Silk Road Economic Belt＂ is to give equal considerations to both the East and the West, paying equal attentions to the North and the South, while balancing the land and the sea and connecting domestic with foreign. This is the innovation and priority of China＇s peripheral diplomacy as well as a strategic support and tactical guarantee of the ＂China Dream＂. The ＂Silk Road Economic Belt＂ is constructed to make history serve reality; it exchanges economy for politics, space on land for time at sea, and balances a weakness in sea power with superiority in land power. Instead of simply replicating the Silk Road, the ＂Silk Road Economic Belt＂ possesses a broader realm and a richer context. Moreover, this is China＇s ultimate strategy and profound tactical conception facing toward the future.
基金financially supported by the National Natural Science Foundation of China (Nos. 31071858 and 41173083)
文摘Overuse of fertilizers and the resultant pollution and eutrophication of surface and groundwater is a growing issue in China. Consequently, improved management strategies are needed to optimize crop production with reduced nutrient inputs. Conventional fertilization （CF）, reduced fertilization （RF）, and reduced fertilization with maize （Zea mays L.） as a summer catch crop （RF＋C） treatments were evaluated in 2008 and 2009 by quantifying tomato （Lycopersieon esculentum） fruit yield and soil nutrient balance in a greenhouse tomato double-cropping system. Fertilizer nitrogen （N） application was reduced by 37% in the RF and RF＋C treatments compared to the CF treatment with no significant reduction in fruit yield. Mean soil mineral N （Nmin） content to a depth of 180 cm following tomato and maize harvest was lower in the RF and RF＋C treatments than in the CF treatment. Residual soil Nmin content was reduced by 21% and 55% in the RF and RF＋C treatments, respectively, compared to the CF treatment. Surplus phosphorus （P） and potassium （K） contents in the RFWC treatment were significantly lower than those in the RF treatment, mainly due to additional P and K uptake by the catch crop. We concluded that for intensive greenhouse production systems, the RF and RF＋C treatments could maintain tomato fruit yield, reduce the potential for nitrate （NO3^--N） leaching, and with a catch crop, provide additional benefits through increased biomass production.
