Watanabe Akira, Ikeya Kosuke, Kanazaki Naoya, Makabe Shuhei, Sugiura Yuki, Shibata Akira
Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan.
Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan.
J Environ Manage. 2014 Nov 1;144:168-75. doi: 10.1016/j.jenvman.2014.05.032. Epub 2014 Jun 18.
The application of char to agricultural land is recognized as a potential way to sequester atmospheric carbon (C) assimilated by plants in soil, thus decelerating global warming. Such a process would also be expected to improve plant growth and the physical and chemical properties of soil. However, field investigations of the effects of continuous char application have not been reported. In the present study, the effects of repetitive bamboo char application on CO2, CH4, and N2O flux from soil, soil C content, and crop yield were investigated at two upland fields over five crop seasons. Three treatments: chemical fertilizer (CF) applied plots (Control plot); cattle manure (CM) (10 t ha(-1)) and CF applied plot (CM plot); and bamboo char (20 t ha(-1)), cattle manure (10 t ha(-1)), and CF applied plot (Char/CM plot), were arranged in each field. After three crop seasons, the fourth treatment with char was applied without CF (Char plot) was given to one of the fields. CM and/or char were applied every crop season. Gas fluxes were measured using the static chamber method. Seasonal variations in CO2 flux and total CO2 emissions were consistently similar between the CM and Char/CM plots and between the Char and Control plots. As such, the decomposition rate of bamboo char was quite small, and the positive or negative effect of char on CM decomposition was not significant in the fields. Soil C analysis provided confirmation of this. CM application enhanced N2O emission mainly in the summer crop season. The differences in total N2O emission between the Char/CM and CM plots as well as between the Char and Control plots were insignificant in most cases. Total CH4 flux was negligibly small in all cases. Although the yield of winter crop (broccoli) in the Char/CM plots was twice observed to be higher than that in the Control and CM plots at one of the fields, in general, the char application had no effect on overall crop yield. Thus, the repeated application of bamboo char had no significant influence on greenhouse gas emissions and crop yields, but a high C accumulating function was found.
将炭施用于农田被认为是一种潜在的方式，可将植物吸收的大气碳（C）固存于土壤中，从而减缓全球变暖。预计这样一个过程还会改善植物生长以及土壤的物理和化学性质。然而，关于持续施用炭的效果的田间调查尚未见报道。在本研究中，在两个旱地农田的五个作物季期间，研究了重复施用竹炭对土壤中二氧化碳、甲烷和氧化亚氮通量、土壤碳含量以及作物产量的影响。每个农田设置了三种处理：施用化肥（CF）的地块（对照地块）；施用牛粪（CM）（10 t ha⁻¹）和CF的地块（CM地块）；以及施用竹炭（20 t ha⁻¹）、牛粪（10 t ha⁻¹）和CF的地块（炭/CM地块）。在三个作物季后，其中一个农田设置了不施CF只施炭的第四种处理（炭地块）。每个作物季都施用CM和/或炭。使用静态箱法测量气体通量。CM地块和炭/CM地块之间以及炭地块和对照地块之间，二氧化碳通量和总二氧化碳排放量的季节变化始终相似。因此，竹炭的分解速率相当小，在田间炭对CM分解的正效应或负效应均不显著。土壤碳分析证实了这一点。施用CM主要在夏季作物季增强了氧化亚氮排放。在大多数情况下，炭/CM地块与CM地块之间以及炭地块与对照地块之间的总氧化亚氮排放量差异不显著。所有情况下总的甲烷通量都小到可以忽略不计。尽管在其中一个农田，炭/CM地块的冬季作物（西兰花）产量有两次被观察到高于对照地块和CM地块，但总体而言，施用炭对作物总产量没有影响。因此，重复施用竹炭对温室气体排放和作物产量没有显著影响，但发现其具有较高的碳积累功能。
