Ma Qing Xu, Wang Jun, Cao Xiao Chuang, Sun Yan, Sun Tao, Wu Liang Huan
Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
hejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou 310058, China.
Ying Yong Sheng Tai Xue Bao. 2017 Jul 18;28(7):2277-2384. doi: 10.13287/j.1001-9332.201707.033.
Organic nitrogen can play an important role in plant growth, and soil pH changed greatly due to the over-use of chemical fertilizers, but the effects of soil pH on the competitive uptake of amino acids by plants and rhizosphere microorganisms are lack of detailed research. To study the effects of soil pH on the uptake of amino acids by maize and soil microorganisms, two soils from Hangzhou and Tieling were selected, and the soil pH was changed by the electrokinesis, then the N-labeled glycine was injected to the centrifuge tube with a short-term uptake of 4 h. Soil pH had a significant effect on the shoot and root biomass, and the optimal pH for maize shoot growth was 6.48 for Hangzhou red soil, while it was 7.65 for Tieling brown soil. For Hangzhou soil, the N abundance of maize shoots under pH=6.48 was significantly higher than under other treatments, and the uptake amount of N-glycine was also much higher. However, the N abundance of maize shoots and roots under pH=7.65 Tieling soil was significantly lower than it under pH=5.78, but the uptake amount of N-glycine under pH=7.65 was much higher. The microbial biomass C was much higher in pH=6.48 Hangzhou soil, while it was much lower in pH=7.65 Tieling soil. According to the results of root uptake, root to shoot transportation, and the competition with microorganisms, we suggested that although facing the fierce competition with microorganisms, the maize grown in pH=6.48 Hangzhou soil increased the uptake of glycine by increasing its root uptake and root to shoot transportation. While in pH=7.65 Tieling soil, the activity of microorganisms was decreased, which decreased the competition with maize for glycine, and increased the uptake of glycine by maize.
有机氮在植物生长中可发挥重要作用，且由于化肥的过度使用，土壤pH发生了很大变化，但土壤pH对植物和根际微生物对氨基酸的竞争性吸收的影响缺乏详细研究。为了研究土壤pH对玉米和土壤微生物吸收氨基酸的影响，选取了杭州和铁岭的两种土壤，通过电动力学改变土壤pH，然后将N标记的甘氨酸注入离心管中进行4小时的短期吸收。土壤pH对地上部和根部生物量有显著影响，杭州红壤中玉米地上部生长的最佳pH为6.48，而铁岭棕壤为7.65。对于杭州土壤，pH = 6.48时玉米地上部的N丰度显著高于其他处理，N-甘氨酸的吸收量也高得多。然而，铁岭土壤pH = 7.65时玉米地上部和根部的N丰度显著低于pH = 5.78时，但pH = 7.65时N-甘氨酸的吸收量要高得多。pH = 6.48的杭州土壤中微生物生物量C高得多，而pH = 7.65的铁岭土壤中则低得多。根据根系吸收、根向地上部运输以及与微生物竞争的结果，我们认为，尽管在pH = 6.48的杭州土壤中生长的玉米面临与微生物的激烈竞争，但它通过增加根系吸收和根向地上部运输来增加甘氨酸的吸收。而在pH = 7.65的铁岭土壤中，微生物活性降低，这减少了与玉米对甘氨酸的竞争，并增加了玉米对甘氨酸的吸收。
