In-field management of corn cob and residue mix: Effect on soil greenhouse gas emissions     

《Applied soil ecology》2015

In-field management practices of corn cob and residue mix (CRM) as a feedstock source for ethanol production can have potential effects on soil greenhouse gas (GHG) emissions. The objective of this study was to investigate the effects of CRM piles, storage in-field, and subsequent removal on soil CO₂ and N₂O emissions. The study was conducted in 2010–2012 at the Iowa State University, Agronomy Research Farm located near Ames, Iowa (42.0°′N; 93.8°′W). The soil type at the site is Canisteo silty clay loam (fine-loamy, mixed, superactive, calcareous, mesic Typic Endoaquolls). The treatments for CRM consisted of control (no CRM applied and no residue removed after harvest), early spring complete removal (CR) of CRM after application of 7.5 cm depth of CRM in the fall, 2.5 cm, and 7.5 cm depth of CRM over two tillage systems of no-till (NT) and conventional tillage (CT) and three N rates (0, 180, and 270 kg N ha⁻¹) of 32% liquid UAN (NH₄NO₃) in a randomized complete block design with split–split arrangements. The findings of the study suggest that soil CO₂ and N₂O emissions were affected by tillage, CRM treatments, and N rates. Most N₂O and CO₂ emissions peaks occurred as soil moisture or temperature increased with increase precipitation or air temperature. However, soil CO₂ emissions were increased as the CRM amount increased. On the other hand, soil N₂O emissions increased with high level of CRM as N rate increased. Also, it was observed that NT with 7.5 cm CRM produced higher CO₂ emissions in drought condition as compared to CT. Additionally, no differences in N₂O emissions were observed due to tillage system. In general, dry soil conditions caused a reduction in both CO₂ and N₂O emissions across all tillage, CRM treatments, and N rates.  相似文献   

Impact of different crop rotations and tillage systems on weed infestation and productivity of bread wheat     

《Crop Protection》2016

Crop rotation and tillage systems have important implications for weed infestation and crop productivity. In this study, five tillage systems viz. zero tillage (ZT), conventional tillage (CT), deep tillage (DT), bed sowing (60/30 cm with four rows; BS₁) and bed sowing (90/45 cm with six rows; BS₂) were evaluated in five different crop rotations viz. fallow-wheat (FW), rice-wheat (RW), cotton-wheat (CW), mungbean-wheat (MW) and sorghum-wheat (SW) for their effect on weed infestation and productivity of bread wheat. Interaction between different tillage practices and cropping systems had significant effect on density and dry biomass of total, broadleaved and grass weeds, agronomic and yield-related traits, and grain yield of bread wheat. The un-disturbed soils (ZT) under fallow-wheat or mungbean-wheat rotations favoured the weed prevalence (a total weed dry biomass of 72.4–109.6 and 105.6–112.1 g m⁻² in first and second year, respectively). Contrary to this, the disturbed soils (CT, DT, BS₁ and BS₂) had less weed infestation with either of the rotations (a total weed biomass of 0.4–7.1 and 1.1–5.4 g m⁻² in first and second year, respectively). Sorghum-wheat rotation had strong suppressive effect on weed infestation in all tillage systems. The impact of crop rotation was more visible during second year of experimentation. Bed sown wheat (BS₁ and BS₂) in mungbean-wheat rotation had the highest wheat grain yield (6.30–6.47 t ha⁻¹) compared to other tillage systems in different crop rotation combinations.  相似文献   

耕作方式对主要粮食作物影响的研究综述          下载免费PDF全文

张向前  杨文飞  徐云姬 《农学学报》2020,10(8):23-27

笔者通过对相关资料的整理与分析,阐述了常见不同耕作方式对主要粮食作物根系特性、光合效应、品质指标及产量的影响,分析了未来农业生产中进一步加强对耕作方式研究的必要性和重要性,并指出今后农业生产中应在结合中国国情的基础上注重根据区域生态环境、土壤属性、作物种类及茬口类型选择适宜的耕作方式,试图为中国农业生产中耕作方式更加合理的选择与运用及作物产量的提高和耕地的可持续利用提供科学依据和理论帮助。  相似文献   

不同耕作方式对辽西褐土物理性状及玉米根系分布的影响     

李嵩  韩巍  张凯  依艳丽 《玉米科学》2020,28(6):101-106

通过连续3年大田试验,对旋耕、翻耕、深松3种耕作方式下的土壤物理性质、玉米根系分布和产量进行测定。结果表明,与翻耕和旋耕相比,深松显著增加了玉米田土壤耕层厚度和降低了犁底层厚度。在中下层土壤,深松还降低了土壤紧实度和容重,改善了土壤的孔隙状况,有利于玉米根系向下生长,使得中下层土壤的玉米根系不仅更丰富,而且占总根系量的比例也更高,最终提高了玉米产量。本研究表明,深松耕作有利于改善辽西褐土区土壤结构和促进玉米生长。  相似文献   

Combined use of optical and radar satellite data for the detection of tillage and irrigation operations: Case study in Central Morocco     

R. Hadria  B. Duchemin  T. Le Toan  G. Dedieu 《Agricultural Water Management》2009,96(7):1120-1127

The objective of this study is to present a new application of optical and radar remote sensing with high spatial (∼10 m) and temporal (a few days) resolutions for the detection of tillage and irrigation operations. The analysis was performed for irrigated wheat crops in the semi-arid Tensift/Marrakech plain (Central Morocco) using three FORMOSAT-2 images and two ASAR images acquired within one week at the beginning of the 2005/2006 agricultural season.The approach we developed uses simple mapping algorithms (band thresholding and decision tree) for the characterisation of soil surface states. The first images acquired by FORMOSAT and ASAR were processed to classify fields into three main categories: ploughed (in depth), prepared to be sown (harrowed), and not ploughed-not harrowed. This information was combined with a change detection analysis based on multitemporal images to identify harrowing and irrigation operations which occurred between two satellite observations.The performance of the algorithm was evaluated using data related to land use and agricultural practices collected on 124 fields. The analysis shows that drastic changes of surface states caused by ploughing or irrigation are detected without ambiguity (consistency index of 96%). This study provided evidence that optical and radar data contain complementary information for the detection of agricultural operations at the beginning of agricultural season. This information could be useful in regional decision support systems to refine crop calendars and to improve prediction of crop water needs over large areas.  相似文献   

不同耕作方式对土壤水分及玉米生长发育的影响   总被引：19，自引：5，他引：19  

宫亮  孙文涛  包红静  王聪翔  孙占祥 《玉米科学》2011,19(3):118-120

针对辽宁省中北部地区土壤耕层变浅、犁地层变硬等问题,以当地传统的耕作方式秋季旋耕为对照,设置秋季旋耕后翻耕25 cm、秋季旋耕后深松30 cm、秋季旋耕后隔年深松30 cm 3种耕作方式,探讨不同耕作方式对土壤水分和玉米生长发育的影响。结果表明,翻耕或深松处理均有利于土壤含水量的提高,其中以秋季旋耕后深松30 cm和秋季旋耕后翻耕25 cm的保墒效果最佳;翻耕或深松处理均增加了根冠比和产量,提高了玉米叶片酶活性,延缓了玉米生育后期叶片的衰老,其中以秋季旋耕后翻耕25 cm效果最佳。秋季旋耕后翻耕25 cm的耕作方式较好。  相似文献   

耕作方式对华北冬小麦.夏玉米周年产量和水分利用的影响   总被引：7，自引：1，他引：7  

孔凡磊  张海林  翟云龙  袁继超  陈阜 《中国生态农业学报》2014,22(7):749-756

在冬小麦季设置秸秆不还田翻耕(CT)、秸秆还田翻耕(CTS)、秸秆还田旋耕(RTS)和免耕秸秆覆盖(NTS)4种处理,研究耕作方式对华北小麦-玉米两熟区作物周年产量和水分利用的影响。结果表明:耕作方式对当季冬小麦产量和水分利用影响显著,对夏玉米产量和水分利用影响不大,但秸秆还田提高了夏玉米产量。RTS、CTS、CT 3个处理小麦季产量差异不显著,而NTS由于有效穗数不足,产量显著低于其他处理;与CT相比,NTS周年产量平均减产5.13%,RTS增产2.69%,CTS增产2.33%。耕作方式对当季小麦土壤水分含量影响大,而对后茬夏玉米土壤水分含量的影响较小。NTS提高了小麦季土壤水分含量,增加了土壤储水量,与CT相比,0~60 cm土壤储水量2010年和2011年分别增加39.07 mm和26.65 mm。从耗水构成来看,土壤水在冬小麦耗水中所占比例最大,其次为灌水和降水;而夏玉米耗水以降水为主,且降水中有一部分转化为土壤水储存起来。NTS提高了冬小麦季土壤储水量,降低了土壤水分的消耗,冬小麦季耗水最少。与CT相比,NTS小麦季平均节水22.40 mm,周年耗水量也以NTS最少;但NTS冬小麦产量降低导致其小麦季和周年水分利用效率均最低。从作物周年产量和水分利用的角度来看,如何提高免耕秸秆覆盖小麦季产量,进而提高周年产量,发挥其节水优势,是该耕作模式在华北地区冬小麦?夏玉米两熟区推广应用亟需解决的关键问题。  相似文献   

长三角地区稻麦轮作土壤养分对秸秆还田响应-Meta分析   总被引：1，自引：1，他引：1  

张志毅  范先鹏  夏贤格  杨利  刘冬碧  张富林  熊桂云  吴茂前  冯婷婷 《土壤通报》2019,(2):401-406

研究旨在明确稻麦轮作下秸秆还田对土壤基础养分的影响。以稻麦轮作系统为研究对象,采用Meta分析方法定量研究了土壤基础养分对秸秆还田的响应及其影响因素。结果表明,短期内(<2年)秸秆还田能够显著提升土壤有机碳和活性有机碳的含量,其中活性有机碳对秸秆还田的响应程度要高于总有机碳。低秸秆还田量(RS <3750 kg hm^-2和WS <3000 kg hm^-2)对土壤基础养分的提升效果不显著,而全量秸秆还田(RS 3000~6000 kg hm^-2和WS 3750~7000 kg hm^-2)能够显著提升土壤速效磷、有机碳和活性有机碳的含量。对于不同耕作措施而言,旋耕或翻耕措施均可以显著提升土壤有机碳的含量;此外,旋耕显著提高全氮和活性有机碳的含量,翻耕显著提高土壤速效磷和速效钾的含量。稻麦轮作下秸秆全量还田配合旋耕或者翻耕措施能够增加土壤基础养分含量,达到土壤地力培育的效果。  相似文献   

华北平原农田生态系统碳过程与环境效应研究   总被引：1，自引：0，他引：1  

胡春胜  王玉英  董文旭  张玉铭  李晓欣  陈素英 《中国生态农业学报》2018,26(10):1515-1520

本文总结了25年来针对华北平原小麦-玉米两熟系统,农田的碳循环对气候变化(温度升高)和管理措施(氮肥施入、秸秆还田和耕作方式等)响应机制的研究成果。自2001年起我们在中国科学院栾城农业生态系统试验站建立了3个长期定位碳循环试验:耕作试验、有机循环试验和增温试验,并完善了4种农田碳过程监测方法体系:隔离罐-碱液吸收CO_2法、静态箱-气相色谱法、涡度相关技术和浓度梯度法。量化了华北平原小麦-玉米两熟系统碳输入-输出的平衡,并对华北平原施氮农田土壤碳截留进行了再评价,指出秸秆还田下高水高肥的精细管理农田正在以77 g(C)·m~(-2)·a~(-1)的速度丢失碳;此外长期氮施入虽然显著增加0~100 cm土体的土壤有机碳含量,但同时会造成0~60 cm土体土壤无机碳含量显著降低。我们在对碳过程环境效应的研究中进一步指出:增温和施氮均会降低CH4汇强度,但对土壤呼吸无显著影响,这可能主要是由于试验增温诱发的土壤干旱抵消了土壤温度的部分影响和土壤呼吸对土壤温度升高的适应性造成的。我们对剖面土壤气体的研究表明施氮对剖面CH4和CO_2均无显著影响。进一步将静态箱法和浓度梯度法相结合的研究结果表明0~40cm土层是北方旱地无氮农田土壤CO_2产生和CH4吸收的主要发生层。  相似文献   

不同施肥措施对白土腐殖质组成的影响   总被引：3，自引：0，他引：3  

吴萍萍  王家嘉  李录久 《土壤》2016,48(1):76-81

以白土稻区4年大田定位试验为基础,设置2种翻耕深度(10 cm、20 cm,分别标记为T10、T20)和4种施肥措施(单施化肥、化肥+畜禽粪肥、化肥+秸秆还田、化肥+绿肥,分别标记为F、F+M、F+S、F+G),通过腐殖质组成修改法分别提取表层土壤水溶性物质、胡敏酸、富里酸和胡敏素,研究不同施肥措施对白土腐殖质各组分碳含量的影响。结果表明:单施化肥措施下,翻耕20 cm处理(T20+F)土壤总有机碳和腐殖质各组分碳含量均低于翻耕10 cm处理(T10+F),但差异未达显著水平。在翻耕20 cm的基础上增施有机肥能显著提高土壤总有机碳和腐殖质各组分碳含量,增施畜禽粪(T20+F+M)、秸秆还田(T20+F+S)和增施绿肥(T20+F+G)3处理的土壤总有机碳、胡敏酸、富里酸和水溶性物质碳含量较T20+F处理分别提高14.57%~30.64%、10.36%~30.57%、0.74%~12.31%和14.25%~26.80%。增施有机肥显著提高胡敏素碳含量,T20+F+M、T20+F+S和T20+F+G处理较T20+F处理提高18.87%~35.78%。4年不同翻耕与施肥措施对白土腐殖质性质未产生显著影响。增施有机肥能一定程度上提高土壤PQ值、胡富比、E4/E6值和色调系数。相关性分析表明,胡敏素、胡敏酸、富里酸碳含量与总有机碳含量间均存在显著或极显著正相关,与水溶性物质碳含量间无明显相关性。  相似文献