短期棉花秸秆生物炭添加对高寒草地苔草和高羊茅生长的影响

Effects of short-term biochar addition of cotton straw on the growth of Carex liparocarpos and Festuca arundinacea Schreb in alpine meadow

探究添加不同施入量与粒径的棉花秸秆生物炭对不同程度退化草地地上植被的修复效果,于巴音布鲁克高寒草地和乌鲁木齐分别进行了3个月的野外原位与室内培养盆栽试验,野外试验观测植物选择苔草(Carex liparocarpos),盆栽试验选用高羊茅(Festuca arundinacea Schreb),以棉花秸秆生物炭为实验材料,设置3种棉花秸秆生物炭粒径:0~0.25、>0.25~1 mm和>1~2 mm;每种粒径下设置3种棉花秸秆生物炭添加量:1%、2%和4%,共计9个施炭处理,以不施炭为施炭对照(CK),以不施炭的未退化区(ND区)为评价修复效果的对照,选取轻度退化区(LD区)和重度退化区(SD区)分别施入棉花秸秆生物炭,共9个棉花秸秆生物炭添加处理和一个不施炭处理,施入3个月后进行植被调查,探究9种不同施炭方案对地上植被高度、盖度、密度、生物量鲜质量与干质量等生长形状的影响。结果表明:野外原位试验和盆栽试验中,不同施炭处理对植物各项指标有不同的影响,但轻度退化区和重度退化区植物各项指标多以T9(>1~2 mm/4%)处理效果最优,双因素方差分析表明:棉花秸秆生物炭添加和退化对植物生长均存在极显著影响(P<0.01),且短期棉花秸秆生物炭添加后粒径对植物生长的影响远大于施入量。采用主成分分析法对地上植物高度、盖度、密度、生物量鲜质量、生物量干质量进行综合评价,在不同退化区的野外与盆栽试验中均以T9(>1~2 mm/4%)处理综合得分最高。综上所述,棉花秸秆生物炭可以作为退化高寒草地的改良材料,野外试验与盆栽试验结果均表明,短期施用棉花秸秆生物炭可促进植物生长,不同粒径棉花秸秆生物炭对植物生长的影响大于施入量,而大粒径(>1~2 mm)棉花秸秆生物炭效果优于中粒径(>0.25~1 mm)和小粒径(0~0.25 mm);高施入量(4%)效果优于中施入量(2%)和低施入量(1%)。在本研究的处理设计中,植物生长指标值随棉花秸秆生物炭粒径增大而增加,随施入量增加而增加,且棉花秸秆生物炭粒径变化对植物的影响大于施入量。粒径>1~2 mm,4%添加棉花秸秆生物炭处理是退化高寒草地短期恢复的最优方案。

Field in situ and indoor culture pot tests were conducted in Bayanbulak Alpine grassland and Urumqi,respectively,to explore the effect of adding biochar with different application amounts and particle sizes on aboveground vegetation restoration in grasslands with different degrees of degradation.The observation plant in the field test was sedge,while that in the pot test was tall fesgrass.Three biochar particle sizes were used(0–0.25 mm,>0.25–1 mm,and>1–2 mm),and three biochar additions were used for each particle size(1%,2%,and 4%),with no carbon application as the control to evaluate the restoration effect.Biochar was applied to the mildly degraded(LD)and severely degraded(SD)zones,and nine biochar-addition treatments and one no-carbon treatment were applied.The vegetation survey was conducted 3 months after application.To explore the short-term restoration effects of nine different carbon application schemes on aboveground vegetation height,coverage,density,fresh biomass weight,and dry weight.The results showed that different carbon application treatments had different effects on plant indices in the field in situ and pot tests,but the T9(>1–2 mm/4%)treatment was the best for plant indices in mildly degraded and severely degraded areas.A two-factor analysis of variance showed that both biochar addition and degradation had significant effects on plant growth(P<0.01).The analysis of biochar application amount and grain size showed that the influence of grain size on plant growth was much greater than that of biochar application amount.The height,cover,density,fresh weight,and dry weight of the aboveground plants were evaluated using principal component analysis,and those of the T9 treatment were the highest in the field and pot experiments in the different degradation areas.Cotton stalk biochar could be used as an improved material for degraded alpine grasslands.Field and pot experiments showed that the short-term application of biochar could promote plant growth,and the effect of different particle sizes of biochar on plant growth was greater than that of the application amount.The effect of large particle size(1–2 mm)was higher than that of medium(>0.25–1 mm)and small(0–0.25 mm)particle sizes.The effect of the high application rate(4%)was higher than that of the medium(2%)and low application rates(1%).In the treatment design of this study,the plant growth index increased with increasing particle size and application amount,and the effect of biochar particle size on plants was greater than that of the application amount.The scheme with>1–2 mm/4%biochar addition is the best for the short-term restoration of mildly and severely degraded alpine grasslands.