生物质炭由于其独特的性质在改良土壤和促进植物生长等方面具有较大的潜力,但施用生物质炭对玉米生长的长期效应尚不明晰。为此本研究在新疆石河子121团炮台土壤改良试验站设置田间原位试验,共设6个施炭处理,分别为不施炭处理(CK)、一次施炭15.75 t.hm^-2(C1)、31.50 t.hm^-2(C2)、63.00 t.hm^-2(C3)和126.00 t.hm^-2(C4)。6年后采集样品,探究施用不同量生物质炭6年后对玉米的生长、养分吸收及光合生理特征的影响。结果表明：(1)施炭显著促进了玉米在苗期和拔节期的株高、茎粗、各器官生物量、叶面积指数、总根长和总根表面积,其中C4处理的增幅最高。(2)在苗期和拔节期各器官养分含量和吸收量随着施炭量的增加而显著增加,其中N吸收量较CK分别增加了32.76%-181.41%,P吸收量增加了60.00%-279.08%,K吸收量增加了40.00%-136.69%,且养分主要在玉米叶片中累积。(3)施炭对苗期玉米的光合生理特征无显著影响,但显著促进了拔节期的净光合速率,气孔导度、蒸腾速率和胞间CO2浓度。其中C4处理增幅最高,净光合速率较CK显著增加了111.01%,气孔导度显著增加了123.23%,蒸腾速率显著增加了108.67%,胞间CO2浓度显著增加了18.88%。光能利用率和水分利用率随着生物质炭施用量的增加呈现先增加后降低的趋势。相关性分析发现,玉米氮、磷、钾吸收量与玉米生长指标、胞间CO2浓度、光能利用率、水分利用率之间呈显著相关,但与净光合速率、气孔导度、蒸腾速率之间无显著相关。

Biochar has great potential in improving soil and promoting plant growth due to its unique properties, but the long-term effect of biochar application on maize growth is still unclear. In this study, a field in-situ experiment was conducted at the 121 regiment battery soil improvement station in Shihezi, Xinjiang. There were six treatments of carbon application, including no carbon application (CK), one-time carbon application of 15.75 t.hm^-2 (C1), 31.50 t.hm^-2 (C2), 63.00 t.hm^-2 (C3) and 126.00 t.hm^-2 (C4). Six years later, samples were collected to explore the effects of different amounts of biochar on maize growth, nutrient absorption and photosynthetic physiological characteristics. The results showed that: (1) Carbon application significantly promoted plant height, stem diameter, biomass of various organs, leaf area index, total root length and total root surface area of Maize at seedling and jointing stages, and C4 treatment had the highest increase. (2) In the seedling stage and jointing stage, the nutrient content and absorption of each organ increased significantly with the increase of carbon application. Compared with CK, N absorption increased by 32.76%-181.41%, P absorption increased by 60.00%-279.08%, K absorption increased by 40.00%-136.69%, and nutrients were mainly accumulated in maize leaves. (3) However, the net photosynthetic rate, stomatal conductance, transpiration rate and intercellular CO2 concentration were significantly increased at jointing stage. Compared with CK, the net photosynthetic rate, stomatal conductance, transpiration rate and intercellular CO2 concentration of C4 increased by 111.01%, 123.23%, 108.67% and 18.88%, respectively. With the increase of biochar application rate, the light use efficiency and water use efficiency first increased and then decreased. Correlation analysis showed that there was a significant correlation between N, P and K uptake and maize growth index, intercellular CO2 concentration, light use efficiency and water use efficiency, but there was no significant correlation between N, P and K uptake and net photosynthetic rate, stomatal conductance and transpiration rate.

国家自然科学(31660073),天山雪松计划(2017XS08)