Laboratory aerobic incubation was conducted for 161 d to study N mineralization and the changes of organic N fractions of nine different manures（3 chicken manures, 3 pig manures and 3 cattle manures） from different ...Laboratory aerobic incubation was conducted for 161 d to study N mineralization and the changes of organic N fractions of nine different manures（3 chicken manures, 3 pig manures and 3 cattle manures） from different farms/locations. Results indicated that significant（P〈0.01 or P〈0.001） difference existed in N mineralization between manures. The rapid N mineralization in manures occurred during 56 to 84 d of incubation. First order exponential model can be used to describe N mineralization from chicken manures and pig manures, while quadratic equation can predict mineralization of organic N from cattle manures. An average of 21, 19 and 13% added organic N from chicken manure, pig manure and cattle manure was mineralized during 161 d of incubation. Amino acid-N was the main source of N mineralization. The changes of amino acid-N together with ammonium N could explain significantly 97 and 96% of the variation in mineralized N from manured soils and manures. Amino acid-N and ammonium N are two main N fractions in determining N mineralization potential from manures. Amino acid-N contributed more to the mineralized N than ammonium N.展开更多
A hydroponic experiment was carried out to study the effect of elevated carbon dioxide(CO2) on root growth of tomato seedlings.Compared with the control(350 μL L-1),CO2 enrichment(800 μL L-1) significantly increased...A hydroponic experiment was carried out to study the effect of elevated carbon dioxide(CO2) on root growth of tomato seedlings.Compared with the control(350 μL L-1),CO2 enrichment(800 μL L-1) significantly increased the dry matter of both shoot and root,the ratio of root to shoot,total root length,root surface area,root diameter,root volume,and root tip numbers,which are important for forming a strong root system.The elevated CO2 treatment also significantly improved root hair development and elongation,thus enhancing nutrient uptake.Increased indole acetic acid concentration in plant tissues and ethylene release in the elevated CO2 treatment might have resulted in root growth enhancement and root hair development and elongation.展开更多
基金financially supported by the National Basic Research Program(973 Program) of China(2013CB127406)
文摘Laboratory aerobic incubation was conducted for 161 d to study N mineralization and the changes of organic N fractions of nine different manures（3 chicken manures, 3 pig manures and 3 cattle manures） from different farms/locations. Results indicated that significant（P〈0.01 or P〈0.001） difference existed in N mineralization between manures. The rapid N mineralization in manures occurred during 56 to 84 d of incubation. First order exponential model can be used to describe N mineralization from chicken manures and pig manures, while quadratic equation can predict mineralization of organic N from cattle manures. An average of 21, 19 and 13% added organic N from chicken manure, pig manure and cattle manure was mineralized during 161 d of incubation. Amino acid-N was the main source of N mineralization. The changes of amino acid-N together with ammonium N could explain significantly 97 and 96% of the variation in mineralized N from manured soils and manures. Amino acid-N and ammonium N are two main N fractions in determining N mineralization potential from manures. Amino acid-N contributed more to the mineralized N than ammonium N.
基金supported by the National Natural Science Foundation of China (No.30871590)the National Key Basic Research Program (973 Program) of China (Nos.2009CB119003 and 2007CB109305)+1 种基金the Major Research Program of Zhejiang Province (No.2008C12061-1)the National "Eleventh Five Years Plan" Key Project on Science and Technology of China (No.2006BAD05B03)
文摘A hydroponic experiment was carried out to study the effect of elevated carbon dioxide(CO2) on root growth of tomato seedlings.Compared with the control(350 μL L-1),CO2 enrichment(800 μL L-1) significantly increased the dry matter of both shoot and root,the ratio of root to shoot,total root length,root surface area,root diameter,root volume,and root tip numbers,which are important for forming a strong root system.The elevated CO2 treatment also significantly improved root hair development and elongation,thus enhancing nutrient uptake.Increased indole acetic acid concentration in plant tissues and ethylene release in the elevated CO2 treatment might have resulted in root growth enhancement and root hair development and elongation.
