氮素形态对油菜秸秆腐解及养分释放规律的影响
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摘要
采用尼龙网袋研究法,研究了不同形态氮素对油菜秸秆腐解及养分释放规律的影响,以期为农业秸秆循环利用和改善秸秆还田效果提供理论依据。试验设置4个处理:不添加氮素(CK)、添加尿素(PU)、添加尿素硝酸铵(UAN)和添加石灰氮(CaCN_2),周期120d。结果表明,油菜秸秆腐解表现为前期快(0～30d)、后期慢(30～120d)的特征。120d时,油菜秸秆累积腐解率为46.08%～52.34%,碳、氮、磷和钾的释放率分别为44.25%～51.52%、51.19%～54.87%、52.82%～58.45%和96.61%～97.46%。添加氮素可以显著促进油菜秸秆腐解。120d时,添加氮素处理较CK处理油菜秸秆的累积腐解率提高10.80%～13.59%。不同形态氮素对秸秆的腐解特征和碳氮磷钾释放速率的效应不同。其中, PU处理秸秆腐解过程分两个阶段,快速腐解(0～30 d)和缓慢腐解(30～120 d); 30 d时油菜秸秆的腐解率达40.39%, 30 d后腐解速率逐渐趋于稳定, 120 d时腐解率达51.06%。UAN处理腐解过程分3个阶段,快速腐解(0～30d)、腐解减缓(30～60d)和缓慢腐解(30～120d);30d时腐解率达40.67%, 30～60 d腐解率上升7.54%, 120 d时腐解率为51.63%。CaCN_2处理的秸秆腐解过程分两个阶段,快速腐解(0～30d)和缓慢腐解(30～120d);其促进腐解作用主要表现在60d后,60d时油菜秸秆腐解率达44.37%,120 d时腐解率为52.34%。与不施氮处理相比, 120 d时UAN处理秸秆累积腐解率提高12.04%,碳、氮和磷累积释放率分别提高9.33%、7.19%和6.97%。各处理对秸秆钾的释放率影响不显著。综合来看,以UAN促进油菜秸秆腐解的效果较为显著。
Excess rape straw causes unreasonable straw processing, such as burning, resulting in resource waste and serious environmental pollution. Returning straw to the soil is an effective way to improve this situation. Previous studies have found that nitrogen can regulate the soil microbial carbon-nitrogen ratio to promote straw decomposition. At present, much research has focused on the effects of nitrogen rate on straw decomposition, whereas the effects of different forms of nitrogen have rarely been proposed. In this experiment, rape straw was returned to soil for 120 days with different forms of nitrogen: urea(PU), urea ammonium nitrate(UAN), and lime nitrogen(CaCN_2), at a 90 kg·hm~(-2) application rate in nylon net bags. The effects of different forms of nitrogen on the decomposition and nutrient release of rape straw were studied. The straw weight and carbon, nitrogen, phosphorus, and potassium contents of straw residues were investigated at 5, 10, 30, 60, 90, and 120 d after straw mixtures were buried into soil to explore characteristics of straw decomposition and nutrient release with the application of different nitrogen forms. The aim of the study was to optimize straw incorporation into soil to improve straw utilization efficiency. The results showed that the decomposition of rape straw was fast in the early stage(0-30 d) and slow in the later stage(30-120 d). At 120 d, the cumulative decomposition rate of rape straw was 46.08%-52.34%. The release rates of carbon, nitrogen, phosphorus and potassium were 44.25%-51.52%, 51.19%-54.87%,52.82%-58.45%, and 96.61%-97.46%, respectively. The addition of nitrogen significantly promoted the decomposition of rape straw.At 120 d, the cumulative decomposition rate of nitrogen treatments increased by 10.80%-13.59% than that of the control treatment.Different forms of nitrogen have different effects on straw decomposition and release rates of carbon, nitrogen, phosphorus and potassium. Among them, the PU treatment decomposition process was divided into two stages, rapid decomposition(0-30 d) and slow decomposition(30-120 d); at 30 d, the decomposition rate of rape straw reached 40.39%. After 30 d, the decomposition rate gradually became stable and reached 51.06% at 120 d. The UAN treatment decomposition process was divided into three stages, rapid decomposition(0-30 d), slowing decomposition(30-60 d), and slow decomposition(30-120 d); the decomposition rate reached40.67% at 30 d. The decomposition rate increased by 7.54% from 30 to 60 d, and it was 51.63% at 120 d. The decomposition effect of the CaCN_2 treatment was mainly manifested after 60 d. At 60 d, the decomposition rate of rape straw reached 44.37%, and was52.34% at 120 d. Overall, the effect of UAN was more significant. Compared with no nitrogen treatment, the cumulative decomposition rate of straw in the UAN treatment increased by 12.04%; the cumulative release rates of carbon, nitrogen, phosphorus increased by 9.33%, 7.19%, and 6.97%, respectively. The effect of each treatment on the potassium release rate of straw was not significant.Therefore, this study provided the basis for enhancing rape straw decomposition to promote straw resource utilization.
Excess rape straw causes unreasonable straw processing, such as burning, resulting in resource waste and serious environmental pollution. Returning straw to the soil is an effective way to improve this situation. Previous studies have found that nitrogen can regulate the soil microbial carbon-nitrogen ratio to promote straw decomposition. At present, much research has focused on the effects of nitrogen rate on straw decomposition, whereas the effects of different forms of nitrogen have rarely been proposed. In this experiment, rape straw was returned to soil for 120 days with different forms of nitrogen: urea(PU), urea ammonium nitrate(UAN), and lime nitrogen(CaCN_2), at a 90 kg·hm~(-2) application rate in nylon net bags. The effects of different forms of nitrogen on the decomposition and nutrient release of rape straw were studied. The straw weight and carbon, nitrogen, phosphorus, and potassium contents of straw residues were investigated at 5, 10, 30, 60, 90, and 120 d after straw mixtures were buried into soil to explore characteristics of straw decomposition and nutrient release with the application of different nitrogen forms. The aim of the study was to optimize straw incorporation into soil to improve straw utilization efficiency. The results showed that the decomposition of rape straw was fast in the early stage(0-30 d) and slow in the later stage(30-120 d). At 120 d, the cumulative decomposition rate of rape straw was 46.08%-52.34%. The release rates of carbon, nitrogen, phosphorus and potassium were 44.25%-51.52%, 51.19%-54.87%,52.82%-58.45%, and 96.61%-97.46%, respectively. The addition of nitrogen significantly promoted the decomposition of rape straw.At 120 d, the cumulative decomposition rate of nitrogen treatments increased by 10.80%-13.59% than that of the control treatment.Different forms of nitrogen have different effects on straw decomposition and release rates of carbon, nitrogen, phosphorus and potassium. Among them, the PU treatment decomposition process was divided into two stages, rapid decomposition(0-30 d) and slow decomposition(30-120 d); at 30 d, the decomposition rate of rape straw reached 40.39%. After 30 d, the decomposition rate gradually became stable and reached 51.06% at 120 d. The UAN treatment decomposition process was divided into three stages, rapid decomposition(0-30 d), slowing decomposition(30-60 d), and slow decomposition(30-120 d); the decomposition rate reached40.67% at 30 d. The decomposition rate increased by 7.54% from 30 to 60 d, and it was 51.63% at 120 d. The decomposition effect of the CaCN_2 treatment was mainly manifested after 60 d. At 60 d, the decomposition rate of rape straw reached 44.37%, and was52.34% at 120 d. Overall, the effect of UAN was more significant. Compared with no nitrogen treatment, the cumulative decomposition rate of straw in the UAN treatment increased by 12.04%; the cumulative release rates of carbon, nitrogen, phosphorus increased by 9.33%, 7.19%, and 6.97%, respectively. The effect of each treatment on the potassium release rate of straw was not significant.Therefore, this study provided the basis for enhancing rape straw decomposition to promote straw resource utilization.
引文
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[2]张福锁.我国肥料产业与科学施肥战略研究报告[M].北京:中国农业大学出版社,2008ZHANG F S.Research Report on Fertilizer Industry and Scientific Fertilization Strategy in China[M].Beijing:China Agricultural University Press,2008
[3]武际,郭熙盛,鲁剑巍,等.不同水稻栽培模式下小麦秸秆腐解特征及对土壤生物学特性和养分状况的影响[J].生态学报,2013,33(2):565-575WU J,GUO X S,LU J W,et al.Decomposition characteristics of wheat straw and effects on soil biological properties and nutrient status under different rice cultivation[J].Acta Ecologica Sinica,2013,33(2):565-575
[4]李逢雨,孙锡发,冯文强,等.麦秆、油菜秆还田腐解速率及养分释放规律研究[J].植物营养与肥料学报,2009,15(2):374-380LI F Y,SUN X F,FENG W Q,et al.Nutrient release patterns and decomposing rates of wheat and rapeseed straw[J].Plant Nutrition and Fertilizer Science,2009,15(2):374-380
[5]BECKER R,BUBNER B,REMUS R,et al.Impact of multi-resistant transgenic Bt maize on straw decomposition and the involved microbial communities[J].Applied Soil Ecology,2014,73:9-18
[6]庞荔丹.玉米秸秆还田腐解率及其对土壤养分影响[D].哈尔滨:东北农业大学,2017PANG L D.Decomposition rate of corn straw returning and its effects on soil nutrients[D].Harbin:Northeast Agricultural University,2017
[7]周永进,吴文革,许有尊,等.油菜秸秆还田培肥土壤的效应及对后作水稻产量的影响[J].扬州大学学报:农业与生命科学版,2015,36(1):53-58ZHOU Y J,WU W G,XU Y Z,et al.Effects of returned rapeseed straw on soil fertility and yield of subsequent rice[J].Journal of Yangzhou University:Agricultural and Life Science Edition,2015,36(1):53-58
[8]ESTHER O J.不同氮源、锌源及外源性微生物添加对小麦玉米秸秆腐解的影响及对土壤质量的作用研究[D].杨凌:西北农林科技大学,2013ESTHER O J.Wheat and maize straw decomposition as influenced by different nitrogen sources,zinc and exogenous microbial compounds and the effects on soil quality[D].Yangling:Northwest A&F University,2013
[9]王允青,郭熙盛.不同还田方式作物秸秆腐解特征研究[J].中国生态农业学报,2008,16(3):607-610WANG Y Q,GUO X S.Decomposition characteristics of crop-stalk under different incorporation methods[J].Chinese Journal of Eco-Agriculture,2008,16(3):607-610
[10]李新举,张志国,李贻学.土壤深度对还田秸秆腐解速度的影响[J].土壤学报,2001,38(1):135-138LI X J,ZHANG Z G,LI Y X.Effects of soil depth on decay speed of straw[J].Acta Pedologica Sinica,2001,38(1):135-138
[11]林心雄,程励励,施书莲,等.绿肥和藁秆等在苏南地区土壤中的分解特征[J].土壤学报,1980,17(4):319-327LIN X X,CHENG L L,SHI S L,et al.Characteristics of decomposition of plant residues in soils of southern part in Jiangsu Province[J].Acta Pedologica Sinica,1980,17(4):319-327
[12]霍竹,付晋锋,王璞.秸秆还田和氮肥施用对夏玉米氮肥利用率的影响[J].土壤,2005,37(2):202-204HUO Z,FU J F,WANG P.Effects of application of N-fertilizer and crop residues as manure on summer maize Nrecovery rate[J].Soils,2005,37(2):202-204
[13]AOYAMA M,NOZAWA T.Microbial biomass nitrogen and mineralization-immobilization processes of nitrogen in soils incubated with various organic materials[J].Soil Science and Plant Nutrition,1993,39(1):23-32
[14]徐国伟,李帅,赵永芳,等.秸秆还田与施氮对水稻根系分泌物及氮素利用的影响研究[J].草业学报,2014,23(2):140-146XU G W,LI S,ZHAO Y F,et al.Effects of straw returning and nitrogen fertilizer application on root secretion and nitrogen utilization of rice[J].Acta Prataculturae Sinica,2014,23(2):140-146
[15]顾炽明.施氮对关中灌区秸秆还田小麦生长及秸秆腐解规律的影响[D].杨凌:西北农林科技大学,2013GU C M.Effect of nitrogen fertilizer application on winter wheat growth and law of maize straw decomposition under maize straw returning in Guanzhong irrigation area[D].Yangling:Northwest A&F University,2013
[16]张亮.关中麦玉轮作区施氮对秸秆还田小麦产量和秸秆养分释放的影响[D].杨凌:西北农林科技大学,2012ZHANG L.Effects of nitrogen fertilizer on yield of winter wheat and straw decomposition under maize straw returning in Guanzhong irrigation district[D].Yangling:Northwest A&F University,2012
[17]胡宏祥,程燕,马友华,等.油菜秸秆还田腐解变化特征及其培肥土壤的作用[J].中国生态农业学报,2012,20(3):297-302HU H X,CHENG Y,MA Y H,et al.Decomposition characteristics of returned rapeseed straw in soil and effects on soil fertility[J].Chinese Journal of Eco-Agriculture,2012,20(3):297-302
[18]武际,郭熙盛,王允青,等.不同水稻栽培模式和秸秆还田方式下的油菜、小麦秸秆腐解特征[J].中国农业科学,2011,44(16):3351-3360WU J,GUO X S,WANG Y Q,et al.Decomposition characteristics of rapeseed and wheat straws under different rice cultivations and straw mulching models[J].Scientia Agricultura Sinica,2011,44(16):3351-3360
[19]宋莉,韩上,鲁剑巍,等.油菜秸秆、紫云英绿肥及其不同比例配施还田的腐解及养分释放规律研究[J].中国土壤与肥料,2015,(3):100-104SONG L,HAN S,LU J W,et al.Study on characteristics of decomposing and nutrients releasing of different proportional mixture of rape straw and Chinese milk vetch in rice field[J].Soil and Fertilizer Sciences in China,2015,(3):100-104
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