[Objective] ln the Mg-deficient （exchangeable Ca/Mg ratio ＆gt; 20） tobacco-growing areas in Qujing City of Yunnan Province, the ratio of Ca/Mg was adjusted by applying Mg fertilizer in soil and spraying Mg fertiliz...[Objective] ln the Mg-deficient （exchangeable Ca/Mg ratio ＆gt; 20） tobacco-growing areas in Qujing City of Yunnan Province, the ratio of Ca/Mg was adjusted by applying Mg fertilizer in soil and spraying Mg fertilizer on tobacco leaves. ln ad-dition, the effects of Mg fertilization on the absorption of K, Ca and Mg in flue-cured tobacco leaves were investigated, providing theoretical basis and production guidance for the balanced fertilization technology in the Mg-deficient flue-cured to-bacco-growing areas in Qujing City of Yunnan Province. [Method] The field plot test and randomized complete block design were adopted in this research. The group without Mg fertilization was treated as control. There were 3 treatment groups for foliar spraying of magnesium-potassium sulfate fertilizer and 2 treatment groups for soil application ＋ foliar spraying of magnesium-potassium sulfate fertilizer. The tobac-co roots, stems, lower leaves, middle leaves and upper leaves were dried and weighed. They were grinded for the determination of K, Ca and Mg content. The total K, Ca and Mg content in upper （B2F）, middle （C3F） and lower （X2F） flue-cured tobacco leaves in each plot was measured. [Result] The foliar spraying and soil application ＋ foliar spraying al increased the absorption of Mg and K in middle and lower tobacco leaves and the absorption of Ca in lower tobacco leaves, but de-creased the absorption of Mg, K and Ca in upper leaves and the absorption of Ca in middle leaves. Among the positions, the accumulated distribution of Mg, K and Ca ranked as middle leaves ＆gt; lower leaves ＆gt; upper leaves. With the application of Mg fertilizer, the Ca/Mg ratio and K/Mg ratio al decreased in middle and upper to-bacco leaves; while the Ca/Mg ratio increased in the lower tobacco leaves, and the K/Mg ratio showed no significant difference among treatment groups. [Conclusion] The foliar spraying and soil application ＋ foliar spraying of magnesium-potassium sulfate fertilizer affected the Ca/Mg ratio and K/Mg ratio in tobacco leaves mainly through affecting the absorption of Mg.展开更多
Magnesium(Mg) and its alloys have emerged as a favored candidate for bio-regenerative medical implants due to their superior biocompatibility, biodegradability and the elastic modulus close to that of human bone. Unfo...Magnesium(Mg) and its alloys have emerged as a favored candidate for bio-regenerative medical implants due to their superior biocompatibility, biodegradability and the elastic modulus close to that of human bone. Unfortunately, the rapid and uncontrollable degradation rate of Mg alloys in chloride-rich body microenvironments limits their clinical orthopedic applications. Recently, Calcium Phosphate(Ca-P)biomaterials, especially Hydroxyapatite(HA), have been broadly applied in the surface functional modification of metal-based biomaterials attributed to their excellent bioactivity and biocompatibility. Hydrothermal modification of Ca-P coatings on Mg alloys has been extensively exploited by researchers for its significant superiorities in controlling coating structure and improving interfacial bonding strength for better osseointegration and corrosion resistance. This work focuses on the up-to-the-minute advances in Ca-P coatings on the surface of Mg and its alloys via hydrothermal methods, including the strategies and mechanisms of hydrothermal modification. Herein, we are inclined to share some feasible and attractive hydrothermal surface modification strategies. From the perspectives of hydrothermal manufacturing technique innovation and coating structure optimization, we evaluate how to foster the corrosion resistance, coating bonding strength, osseointegration and antibacterial properties of Mg alloys with Ca-P coatings synthesized by hydrothermal method. The challenges and future perspectives on the follow-up exploration of Mg alloys for orthopedic applications are also elaborately proposed.展开更多
Field and glasshouse experiments were conducted to study the effect of B. japonicum inoculation and phosphorus supplementation on macronutrient uptake by soybean. The treatments consisted of B. japonicum inoculation (...Field and glasshouse experiments were conducted to study the effect of B. japonicum inoculation and phosphorus supplementation on macronutrient uptake by soybean. The treatments consisted of B. japonicum inoculation (with & without), phosphorus supplementation at the levels of 0, 20, 40 and 80 kg P·ha-1. Both treatments were replicated four times in a split plot design. The macronutrients considered were N, P, K, Ca and Mg. Results showed that inoculation with B. japonicum significantly contribute to the uptake of N, P, K, Ca and Mg in roots, shoots, pods and the whole soybean plant. Likewise, phosphorus supplementation significantly enhanced the uptake of N, P, K, Ca and Mg in roots, shoots, pods and the whole plant. The use of effective strains of rhizobia and P supplementation was an effective way of enhancing the growth of soybean, eventually the uptake of macronutrients in plant organs.展开更多
基金Supported by National Science and Technology Support Program(2012BAD40B02)Science and Technology Plan Project of Yunnan Tobacco Company(2012YN48)~~
文摘[Objective] ln the Mg-deficient （exchangeable Ca/Mg ratio ＆gt; 20） tobacco-growing areas in Qujing City of Yunnan Province, the ratio of Ca/Mg was adjusted by applying Mg fertilizer in soil and spraying Mg fertilizer on tobacco leaves. ln ad-dition, the effects of Mg fertilization on the absorption of K, Ca and Mg in flue-cured tobacco leaves were investigated, providing theoretical basis and production guidance for the balanced fertilization technology in the Mg-deficient flue-cured to-bacco-growing areas in Qujing City of Yunnan Province. [Method] The field plot test and randomized complete block design were adopted in this research. The group without Mg fertilization was treated as control. There were 3 treatment groups for foliar spraying of magnesium-potassium sulfate fertilizer and 2 treatment groups for soil application ＋ foliar spraying of magnesium-potassium sulfate fertilizer. The tobac-co roots, stems, lower leaves, middle leaves and upper leaves were dried and weighed. They were grinded for the determination of K, Ca and Mg content. The total K, Ca and Mg content in upper （B2F）, middle （C3F） and lower （X2F） flue-cured tobacco leaves in each plot was measured. [Result] The foliar spraying and soil application ＋ foliar spraying al increased the absorption of Mg and K in middle and lower tobacco leaves and the absorption of Ca in lower tobacco leaves, but de-creased the absorption of Mg, K and Ca in upper leaves and the absorption of Ca in middle leaves. Among the positions, the accumulated distribution of Mg, K and Ca ranked as middle leaves ＆gt; lower leaves ＆gt; upper leaves. With the application of Mg fertilizer, the Ca/Mg ratio and K/Mg ratio al decreased in middle and upper to-bacco leaves; while the Ca/Mg ratio increased in the lower tobacco leaves, and the K/Mg ratio showed no significant difference among treatment groups. [Conclusion] The foliar spraying and soil application ＋ foliar spraying of magnesium-potassium sulfate fertilizer affected the Ca/Mg ratio and K/Mg ratio in tobacco leaves mainly through affecting the absorption of Mg.
基金supported by National Natural Science Foundation of China(Grant No.51872197,81772363 and 81972076)Shanghai Committee of Science and Technology,China(Grant No.15411951000)。
文摘Magnesium(Mg) and its alloys have emerged as a favored candidate for bio-regenerative medical implants due to their superior biocompatibility, biodegradability and the elastic modulus close to that of human bone. Unfortunately, the rapid and uncontrollable degradation rate of Mg alloys in chloride-rich body microenvironments limits their clinical orthopedic applications. Recently, Calcium Phosphate(Ca-P)biomaterials, especially Hydroxyapatite(HA), have been broadly applied in the surface functional modification of metal-based biomaterials attributed to their excellent bioactivity and biocompatibility. Hydrothermal modification of Ca-P coatings on Mg alloys has been extensively exploited by researchers for its significant superiorities in controlling coating structure and improving interfacial bonding strength for better osseointegration and corrosion resistance. This work focuses on the up-to-the-minute advances in Ca-P coatings on the surface of Mg and its alloys via hydrothermal methods, including the strategies and mechanisms of hydrothermal modification. Herein, we are inclined to share some feasible and attractive hydrothermal surface modification strategies. From the perspectives of hydrothermal manufacturing technique innovation and coating structure optimization, we evaluate how to foster the corrosion resistance, coating bonding strength, osseointegration and antibacterial properties of Mg alloys with Ca-P coatings synthesized by hydrothermal method. The challenges and future perspectives on the follow-up exploration of Mg alloys for orthopedic applications are also elaborately proposed.
文摘Field and glasshouse experiments were conducted to study the effect of B. japonicum inoculation and phosphorus supplementation on macronutrient uptake by soybean. The treatments consisted of B. japonicum inoculation (with & without), phosphorus supplementation at the levels of 0, 20, 40 and 80 kg P·ha-1. Both treatments were replicated four times in a split plot design. The macronutrients considered were N, P, K, Ca and Mg. Results showed that inoculation with B. japonicum significantly contribute to the uptake of N, P, K, Ca and Mg in roots, shoots, pods and the whole soybean plant. Likewise, phosphorus supplementation significantly enhanced the uptake of N, P, K, Ca and Mg in roots, shoots, pods and the whole plant. The use of effective strains of rhizobia and P supplementation was an effective way of enhancing the growth of soybean, eventually the uptake of macronutrients in plant organs.
