应加大秸秆生物质炭化产业支持

正近年来,农作物秸秆焚烧成为大气污染的重要源头,也造成大量的资源浪费。建议加大秸秆生物质炭化产业支持,综合利用秸秆,促进我国生态农业可持续发展。一是将秸秆炭化还田循环利用方案体现在国家农业绿色发展战略中。二是加大秸秆炭化还田补贴力度,提高项目所需工业用地选址、项目立项审批等效率,支持秸秆炭化还田技术快速推广。三是在全国范围内组织开展秸秆炭化还田-土     

秸秆还田配合施钾对土壤钾的盈亏影响

研究秸秆还田及秸秆还田配合施钾对三大土壤类型土壤中钾的盈亏影响 ,结果表明 ,潮土和褐土区中小麦 玉米轮作制下 ,施钾配合秸秆还田 (NPKM)处理 ,能够保持整个周期循环中钾的平衡 ,归还率达 10 9.1%～111.9%。其中每年还田的小麦秸秆可以提供 2 2 6 .5～ 2 6 1.0 kg/ hm2钾的归还量。而不实行秸秆还田的施钾处理(NPK处理 ) ,钾归还率为 95 .2 %～ 97.1%。在砂姜黑土区小麦 大豆轮作制度下 ,即使小麦秸秆不还田 ,仅施用化学钾肥 ,亦能维持小麦大豆轮作周期钾素的平衡。施钾配合秸秆还田 (NPKM)处理 ,钾归还率达 14 2 .0 % ,施钾且秸秆不还田 (NPK)处理钾归还率达 119.9%。主要是大豆不象玉米那样带走较多的钾造成的     

寒地黑土秸秆还田对土壤养分含量及玉米产量的短期效应

试验研究了玉米秸秆带状还田对当年土壤养分含量和玉米产量的影响,为黑龙江省黑土区秸秆还田策略提供理论依据。试验在黑龙江省高纬度寒区开展,于2022年春季设置秸秆离田（CK）、整株秸秆带状还田（T1）、粉碎秸秆带状还田（T2）和粉碎秸秆配施有机肥带状还田（T3）4个处理。结果表明：短期内,秸秆带状还田不同模式对土壤养分指标和玉米产量构成指标有不同影响,与CK相比,T3处理土壤有机质和全氮含量分别增加7.62%和9.75%,电导率减少9.21%,玉米穗长增加8%以上,行粒数增加6.98%,单棒重增加23.61%,产量增加24.05%。通过主成分分析和典型相关分析,发现秸秆不同带状还田模式对土壤有机质和全氮影响的权重高于其他养分指标,对玉米产量构成指标影响较大的是单棒重、穗长和百粒重;土壤有机质、全氮含量与玉米单棒重、穗长和百粒重呈正相关性,而土壤电导率与玉米单棒重、穗长和百粒重呈负相关性。     

秸秆生物质能综合利用评价方案指标体系研究——以徐州市为例

为了避免徐州市秸秆生物质能项目的盲目发展,需要对秸秆资源进行评估和全面规划。本文利用层次分析法对徐州市秸秆生物质能的利用方案进行综合指标评价,得到各层次的排序,得出徐州市在未来几年应该重点发展秸秆发电和秸秆还田项目;最后根据徐州市秸秆生物质能利用方案的评价结果,从政策扶持、技术研发和统筹规划三个方面提出了秸秆生物质能综合利用的措施建议。     

科技动态

推广秸秆还田我国农村秸秆还田技术推广迅速,已发展到4亿亩,比1989年的3亿亩增长33%,成为仅次于农家肥的有机肥料。我国农作物秸秆资源十分丰富,年产量5亿多吨。目前利用方法有两种。一是焚烧成草木灰;二是制作青贮饲料和氨化秸秆,1991年分别达到4100和370万吨以上,占秸秆总量的8.2%,用以喂养家畜,相当于年节粮760多万吨。秸秆过腹还田,增加畜产品、节约粮食,还增强土壤、蓄水保肥能力。     

秸秆还田条件下不同施氮量对玉米产量及土壤养分的影响

以夏玉米为研究对象,通过田间试验研究了定量秸秆还田条件下不同施氮量在玉米上的效应,以明确定量秸秆还田和不同氮量配施对玉米生长、氮素利用率和土壤养分的影响,为秸秆还田和科学施氮提供理论和实践依据。试验结果表明:在定量秸秆6000 kg/hm~2还田条件下,能有效提高玉米穗数、穗粒数、千粒重和产量,施氮量在180.0~270.0 kg/hm~2时增产效果显著,比施氮量75.0 kg/hm~2和150.0 kg/hm~2增产20.33%~26.15%;秸秆还田配施氮量180.0~300.0 kg/hm~2,能有效提高玉米植株吸氮量、氮肥利用率并降低土壤氮素依存率,是田间试验条件下玉米种植定量秸秆6000 kg/hm~2还田的最优配施氮量范围;在秸秆还田条件下,不同施氮量可以微调玉米根区土壤酸碱度;配施氮量270.0~300.0 kg/hm~2时,可有效提升土壤中全氮含量,并有效调节土壤有效磷和速效钾含量。     

我国秸秆综合利用技术进展与展望

我国的秸秆资源总量位居世界第一,但秸秆的收集贮运、综合利用等体系尚未完善。秸秆的随意丢弃、露天焚烧在浪费资源的同时还引起了严重的环境问题。文章综述了我国秸秆还田、秸秆发电、秸秆制醇、秸秆造纸等秸秆综合利用的技术进展及其在工业中的应用。同时针对当前秸秆综合利用存在的一些问题提出了几点建议,希望对未来我国秸秆综合利用技术及产业的发展有所帮助。     

麦套稻田杂草发生特点及综合防治技术

麦田套稻是集免耕、免插和秸秆大量还田于一体的轻型栽培技术 ,具有节省秧田、肥田改土、省工节本、增产增收等显著特点 ,秸秆大量或全量还田可避免资源的浪费和长期困扰人们由于焚烧秸秆带来的环境污染问题 ,这项农业栽培技术有利于农业生产可持续发展 ,符合我国现代农业和生态农业的发展方向。但由于其栽培技术的特点 ,杂草危害尤显突出 ,主要表现在杂草发生早、延续期长、种类多、数量大、危害重等方面。为控制杂草、减轻草害 ,作者于 2 0 0 0～ 2 0 0 1年根据麦套稻栽培技术及田间杂草发生的特点 ,对麦套稻田的杂草综合防除技术进行了试…     

秸秆还田配施不同用量有机物料腐熟剂对水稻产量、土壤性质的影响

以腐植酸控释掺混肥为基肥,研究了小麦秸秆还田下配施不同用量有机物料腐熟剂对水稻产量、土壤养分含量、土壤微生物数量和土壤酶活性等的影响,并筛选适宜的添加量。结果表明:同等施肥条件下,秸秆还田配施不同用量的有机物料腐熟剂,均可提高水稻的产量。与对照相比,添加有机物料腐熟剂为2、4和6 kg/667 m~2时,水稻的经济产量分别显著提高了3.68%、8.96%和7.17%,即有机物料腐熟剂添加量为4 kg/667 m~2时增产效果最显著。此外,添加不同用量的有机物料腐熟剂均显著提高了土壤养分含量、土壤酶活性和土壤微生物数量。因此,秸秆还田配施适宜用量的有机物料腐熟剂可加速秸秆降解,改善土壤微生物群落组成和数量,提高土壤酶活性和土壤养分含量,最终提高作物产量和经济效益。     

利用重组里氏木霉高效降解秸秆的研究

秸秆还田对于减少化肥使用量、改善土壤生态环境等具有重要作用。本文采用重组里氏木霉对秸秆进行快速降解研究,结果表明,重组里氏木霉在固态发酵中对湿度(60%～75%)、温度(24～32℃)的适应范围较宽,10%氨水常温预处理可加速秸秆的降解进程。重组里氏木霉在秸秆基质中可迅速生长并分泌纤维素酶、漆酶和木聚糖酶,其中滤纸酶活力(即纤维素酶总活力)第8天开始趋于平稳,最终活力为132.26 IU?g~(-1);内切型-β-葡聚糖酶(CMC酶)、漆酶和木聚糖酶活力在第10天达到峰值,分别为1313.15、8.11和5504.10 IU?g~(-1)。接种后第10天,秸秆纤维素、半纤维素和木质素的降解率分别为77.93%、55.12%和31.52%。重组里氏木霉的秸秆降解率比出发菌株及枯草芽孢杆菌分别提高了45.40%和76.37%。本文的研究结果对于进一步提高秸秆快速降解还田技术,改善生态环境具有重要意义。     

Effects of decomposing rice straw on growth of and nitrogen fixation byRhizobium

Five phenolic compounds produced by decomposing rice straw and sterile extracts of decomposing rice straw in soil were very inhibitory to growth of three strains ofRhizobium. The effects were additive and in several instances synergistic. The phenolic compounds also reduced nodule numbers and hemoglobin content of the nodules in two bean (Phaseolus vulgaris) varieties. Extracts of decomposing rice straw in soil (same concentration as in the soil) significantly reduced N₂ fixation (acetylene reduction) in Bush Black Seeded beans. This may explain in part the great reduction in soybean yields in Taiwan following rice crops when the rice stubble is left in the field.     

Effects of rice straw returning methods on N<Subscript>2</Subscript>O emission during wheat-growing season

A field experiment was conducted in Jurong of Nanjing, Jiangsu Province, China from 2006 to 2008 to investigate N₂O emission during the wheat-growing season as affected by various rice straw returning methods prior to wheat cultivation. The study was designed to have four treatments: no rice straw applied (CK), rice straw burnt in situ (RB), rice straw evenly incorporated into the topsoil (RI), rice straw evenly spread over the field as mulch (RM). Results showed that N₂O emission was decreased by 24–29% in Treatment RB and by 3–18% in Treatment RI, but increased by 15–39% in Treatment RM, compared with that in Treatment CK. The contents of soil total C and N at wheat harvest were significantly increased by 7–13% and by 8–12% in Treatment RI, respectively, compared with that in Treatment CK. The wheat grain yield in Treatment RI was 1.0–1.2 times that in the Treatment CK. Based on these results, the best management practice of returning rice straw to the soil prior to wheat cultivation is evenly incorporating rice straw into the topsoil, as the method tended to reduce N₂O emission during the wheat-growing season and increase wheat yield and soil fertility.     

25%吡蚜酮·噻虫嗪悬浮剂在水稻生态系统中的残留检测和消解动态

运用高效液相色谱分析技术测定25%吡蚜酮·噻虫嗪悬浮剂在稻田水、土壤、植株和糙米中的消解动态和最终残留。吡蚜酮在稻田水、土壤和植株中的消解动态方程分别为c=0.134e^-0.12t,C=1.377e^-0.13t及C=0.741e^-0.10t。噻虫嗪在稻田水、土壤和植株中的消解动态方程分别为C=0.114e^-0.12t,C=1.118e^-0.10t及C=0.626e^-0.12t。最终残留结果显示,25%吡蚜酮·噻虫嚷悬浮剂施用剂量为0.0525～0.0788g/m²时,施药距水稻的安全收获间隔期为21d。     

40%稻丰散水乳剂在水稻及稻田环境中的残留动态研究

测定了稻丰散在水稻及稻田环境的残留动态情况。以丙酮、乙腈或二氯甲烷提取水稻、土壤及水样中的稻丰散残留,稻苗样品过SPE小柱净化,稻壳和糙米直接浓缩、定容,最后用GC-ECD（气相色谱仪带电子捕获检测器）测定。稻丰散在土壤、田水、稻杆（苗）、糙米和稻壳中的添加回收率为83.8%～117.2%。稻丰散在三地田水、土壤和稻苗中的消解半衰期分别为0.92～1.71 d、8.2～16.1 d和2.59～4.30 d。按推荐剂量的1.5倍施药3～4次,距最后一次施药间隔21 d后,稻杆中最终残留量≤0.019～2.05 mg/kg,稻壳中最终残留量≤0.234～4.19 mg/kg,糙米中最终残留量≤0.001～0.040 mg/kg。暂以稻丰散在糙米中的最高残留限量为0.05 mg/kg,糙米距采收期最后一次施药21 d是安全的,但稻壳慎用。     

Effect of wheat straw application on ammonia volatilization from urea applied to a paddy field

A proper amount of nitrogen (N) fertilizer is critical for the ideal production in the wheat-rice rotation in the Yangtse Delta region of China and straw retention is important for sustaining soil quality and productivity. However, the effects of straw retention on paddy field ammonia volatilization from applied urea are unclear. The objectives of this study were to explore the effect of wheat straw retuned with urea and to evaluate how floodwater ammonium concentration and pH, soil Eh influence on flooded rice field ammonia volatilization. The study was conducted for 2?years using a lysimeter experiment included 5 treatments, urea applied at rates of 0, 180, 240?kg?N?ha^?1 with no retained straw, and at rates of 180 and 240?kg?N?ha^?1 with 6.5?t?ha^?1 of retained wheat straw. Urea was split into three applications: incorporated at transplanting, tillering, and topdressing at panicle emergence. Rice was flooded to a depth of 5?cm and grown in rotation with irrigated wheat as a source of straw. Averaged over the two levels of applied N, straw incorporation increased the floodwater ammonium concentration by 11.5?C22.5?%, pH by 0.13?C0.70 units but reduced topsoil Eh by 1.0?C47?mv. Ammonia volatilization increased with the increasing amounts of urea applied and with straw incorporated. With no retained straw, the average ammonia volatilization from the fertilized treatments was 40.4?kg?N?ha^?1, accounting for 15.8?% of the fertilizer-N. With retained wheat straw, the average ammonia volatilization from the fertilized treatments was 51.9?kg?N?ha^?1, accounting for 21.3?% of the fertilizer-N. The increase in ammonia volatilization caused by straw incorporation may be partly attributed to the presence of urease in the straw and to the increased pH in the floodwater. It is unclear whether the reduced redox potential also contributed to ammonia volatilization.     

Nitrogen-15 balance as affected by rice straw management in a rice-wheat rotation in northwest India

The sustainability of the productive rice-wheat systems of Northwest India is being questioned due to the complete removal of straw for animal consumption and fuel, or the burning of straw which has reduced the soil organic matter contents. However, straw incorporation at planting can temporarily reduce the availability of fertilizer-N and reduce crop yields. In a field study on a loamy sand soil, the effect of 6 mg ha⁻¹ rice straw incorporated into the soil 20 or 40 days before sowing (DBS) the wheat was compared with removal or burning of rice straw on the fate and balance of 120 kg ha⁻¹ of 5 atom% ¹⁵N-urea applied to wheat and to a following crop of rice. Wheat grain yield and agronomic efficiency (AE) of applied N (kg grain/kg N applied) were not influenced by rice straw management. However, N uptake (NU), and recovery efficiency (RE) of N by the difference method were lower with rice straw incorporation than with burning. Nitrogen-15 recovery by wheat was highest (41%) when the rice straw was removed or burned and lowest (30.4%) when 30 of the 120 kg N ha⁻¹ was applied at the time of straw incorporation at 20 DBS of wheat. However, this strategy of adding 25% of the urea-N dose at the time of straw incorporation resulted in the highest ¹⁵N losses (45.2%). Inorganic N remaining at harvest in the 0 to 60 cm soil profile, mostly NO₃ ⁻, was 5.5% after wheat and 4.2% after rice. Rice grain yields, NU, and RE were not influenced by rice straw management. Nitrogen-15 losses were similar in rice and wheat (31% with straw removed) despite total irrigation and rainfall inputs of 340 and 32 cm to rice and wheat, respectively. These results suggest to the farmers of northwest India that straw incorporation does not necessarily hurt grain yields, and indicates to researchers that work is still needed to improve N use efficiency in rice and wheat. This revised version was published online in June 2006 with corrections to the Cover Date.     

认识尿素，用好尿素——尿素的农业化学性质与合理施用

尿素是我国目前最重要的氮肥品种,2007年我国生产了约5100万t尿素。文章较系统地介绍和评价了尿素的农业化学性质,如尿素的分解、聚合和氨挥发等;讨论了合理施用尿素的若干基本原则,如不离水不离根、先肥土后肥苗、慎小苗、控制量等.     

Efficiency of N-(n-butyl) thiophosphoric triamide in retarding hydrolysis of urea and ammonia volatilization losses in a flooded sandy loam soil amended with organic materials

Using a forced-draft chamber technique, the suppression of NH3 volatilization losses by applying N-(n-butyl) thiophosphoric triamide (NBPT) was studied in an alkaline sandy loam soil amended with green manure or wheat straw. Applied urea was completely hydrolysed in 12, 8 and 6 days in unamended, green manure and wheat straw amended soil, respectively. By applying 0.5% (w/w of urea) NBPT, complete hydrolysis of urea was delayed up to 16 days in the unamended soil, whereas in wheat straw amended soil urea hydrolysis was completed by the 12th day even when it was treated with 2% NBPT. Applied at 1 or 2% level, NBPT delayed the NH3 volatilization to the 4th day after application of urea in green manure or wheat straw amended soil. Hydrolysis of urea was more effectively retarded by applying NBPT in the unamended soil than in soil amended with green manure or wheat straw. In the unamended soil, 7.1% of the applied urea was lost through NH3 volatilization. The losses were reduced to 1.2 and 0.7% by applying 0.5 and 1% NBPT, respectively. Enhanced NH3 volatilization caused by the green manure or wheat straw was counteracted by applying NBPT.     

Nitrogen and residue management effects on agronomic productivity and nitrogen use efficiency in rice–wheat system in Indian Punjab

Development of a sustainable and environment friendly crop production system depends on identifying effective strategies for the management of tillage and postharvest crop residues. Three-year (2004–2007) field study was initiated on two soil types to evaluate the effect of straw management (burning, incorporation and surface mulch) and tillage (conventional tillage and zero tillage) before sowing wheat and four nitrogen rates (0, 90, 120 and 150 kg N ha⁻¹) on crop yields, N use efficiency, and soil fertility in the northwestern India. Effect of tillage and straw management on nitrogen transformation in soils was investigated in a laboratory incubation study. In sandy loam, grain yield of wheat with straw mulch-zero-till (ZT) was 7% higher compared to when residues were burnt-ZT but it was similar to straw burnt-conventional till (CT), averaged across 3 years. In silt loam, grain yield of wheat with straw mulch-ZT was 4.4% higher compared to straw incorporated-CT, but it was similar to straw burnt-CT. Response to N application was generally observed up to 150 kg N ha⁻¹ except in 2004–2005 on sandy loam where N response was observed up to 120 kg N ha⁻¹, irrespective of straw and tillage treatments. In sandy loam, RE was lower (49%) for straw burnt-ZT than in other treatments (54–56%). In silt loam, RE was higher in straw mulch-ZT compared with straw incorporation-CT (65 vs. 58%). In sandy loam, AE was higher in straw burnt-CT and straw mulch-ZT compared with the other treatments (19.2 vs. 16.9 kg grain kg⁻¹ N applied). In silt loam, AE was lower in straw incorporation-CT than in other treatments (16.0 vs. 17.6 kg grain kg⁻¹ N applied). Rice yield and N uptake were not influenced by straw and tillage management treatments applied to the preceding wheat. Recycling of rice residue (incorporation and surface mulch) compared with straw burning increased soil organic carbon and the availability of soil P and K. There was more carbon sequestration in rice straw mulch with zero tillage (25%) than in straw incorporation with conventional tillage (17%). Soil N mineralization at 45 days after incubation was 15–25% higher in straw retention plots compared with on straw burnt plots.     

冬小麦生育期不同保水措施土壤水分变化研究

研究了不同保水措施及灌水对小麦田表层土壤保水及入渗性能的影响。结果表明,总的趋势是随着保水剂用量的增加,保水性能增强。在越冬期内,秸秆覆盖下的土壤表层水分略高于保水剂处理;从返青期到孕穗期,灌水和不灌水处理的土壤表层水分消耗差异明显,灌水处理的表层土壤含水量比不灌水处理下降的多;在孕穗后期,灌水处理表层土壤含水量明显高于不灌水处理,且随保水剂用量增加而增加,秸秆覆盖处理稍低于保水剂处理;收获后,处理间差异不显著。在土壤导水方面,耕作和保水措施都提高了土壤渗透性能,传统耕作和灌水处理均降低了土壤饱和导水率。灌水条件下,保水剂用量45kg／hm^2时有利于提高土壤饱和导水率。