氨化秸秆还田改善土壤结构增加冬小麦产量

为探索一种能够充分发挥秸秆改良土壤结构和提高作物产量作用的秸秆还田措施,通过2 a小区试验,对比研究了粉碎、氨化秸秆以及与无机土壤改良剂(硫酸钙)混合施用措施对农田土壤结构及冬小麦产量的影响。结果表明,粉碎并氨化秸秆施入土壤后,能显著(P0.05)降低耕层(0~15 cm)土壤的体积质量,增加土壤孔隙度,但对耕层以下(15~30 cm)土壤体积质量及孔隙度改善效果不明显;氨化秸秆施入土壤后较未氨化秸秆能显著(P0.05)增加0~15 cm土壤中0.25 mm土壤团聚体含量,粉碎并氨化秸秆能显著(P0.05)降低土壤团聚体分形维数,提高0~15 cm土壤平均重量直径和几何平均直径各项评价指标。此外,穗粒数、1 m2有效穗数、千粒质量和地上部总干质量与籽粒产量的相关系数分别为0.30(P0.05)、0.76(P0.01)、-0.89(P0.01)和0.88(P0.01),提高冬小麦有效穗数或地上部总干质量可能是增加作物产量的主要途径。粉碎并氨化秸秆还田较秸秆覆盖能显著(P0.05)提高冬小麦有效穗数;粉碎并氨化秸秆与无机土壤改良剂(硫酸钙)混合施用措施提高冬小麦产量效果最为显著,在冬小麦2个生长季较长秸秆覆盖还田分别增产11.12%和17.85%,较长秸秆翻压还田分别增产7.39%和16.59%,是该试验最佳秸秆还田方式。该研究成果可为干旱、半干旱地区改良秸秆还田措施、提高作物产量提供理论依据。     

冬小麦土壤电导率与其产量的相关性

以冬小麦品种京冬12为试验对象,采用1：5土水浸提液的方法在整个冬小麦生长周期测量了土壤电导率。冬小麦产量由带有全球定位系统的联合收割机获得,定位系统可以记录小区位置。使用统计方法对冬小麦在不同生长期的土壤电导率和产量进行了相关分析,线性分析结果表明冬小麦在抽穗期以后两者间有一定线性关系。建立了冬小麦在抽穗期、乳熟期和灌浆期土壤电导率值和产量的关系模型,模型的决定系数R2均大于0.630,其中灌浆期模型的决定系数最高达到0.678,表明应用土壤电导率建立产量预测模型可以得到较好的结果。试验结果表明,土壤电导率作为一种复杂的土壤理化参数,可以作为土壤生产潜力的评价指标,可以用来评估作物产量、定义管理区和为精细农业提供变量处方管理。     

Straw return decreases polycyclic aromatic hydrocarbon (PAH) accumulation in winter wheat and human health risk by enhancing PAH dissipation in rhizosphere soil

Straw return in situ, a common agronomic measure in China, has been widely used not only to increase crop yields and improve soil nutrients but also to remove polycyclic aromatic hydrocarbons (PAHs) from agricultural soils. Nevertheless, the safety risks of food crops (i.e., human health risk of wheat grains) grown in PAHs-contaminated agricultural soils amended with crop straw remain uncertain. A pot experiment was conducted in a PAHs-contaminated agricultural soil cultivated with winter wheat under different ratios of corn straw addition (0% (control, CK), 1%, 2.5%, and 5%, weight/weight). Results showed that corn straw addition significantly (P < 0.05) decreased PAH concentrations in rhizosphere soil, roots, straws, and grains by 48.32%–50.01%, 11.85%–42.67%, 9.78%–28.03%, and 14.16%–31.67%, respectively, compared with CK, whereas the transfer factors of PAHs from roots to straws were significantly (P < 0.05) increased. A correlation heatmap showed that PAH concentrations in roots, straws, and grains were positively (P < 0.01) correlated with those in rhizosphere soil. These indicated that corn straw decreased PAH accumulation in winter wheat due to the increase of PAH dissipation in the rhizosphere soil, although it enhanced PAH transfer in winter wheat. The incremental lifetime cancer risk (ILCR) model indicated that corn straw significantly (P < 0.05) decreased the human health risk of winter wheat grains by 29.73%–45.05%. Overall, corn straw apparently reduced PAH accumulation in winter wheat, ecological risk, and human health risk via enhancing PAH dissipation in the rhizosphere soil. These findings provide an important scientific basis and theoretical guidance for agricultural safety production.     

Effects of various cover crops after peas on nitrate leaching and nitrogen supply to succeeding winter wheat or potato crops

In organic farming systems, it has been demonstrated that grain pulses such as peas often do not enhance soil N supply to the following crops. This may be due to large N removals via harvested grains as well as N‐leaching losses during winter. In two field‐trial series, the effects of legume (common vetch, hairy vetch, peas) and nonlegume (oil radish) cover crops (CC), and mixtures of both, sown after peas, on soil nitrate content, N uptake, and yield of following potatoes or winter wheat were studied. The overall objective of these experiments was to obtain detailed information on how to influence N availability after main‐crop peas by adapting cover‐cropping strategies. Cover crops accumulated 56 to 108 kg N ha^–1 in aboveground biomass, and legume CC fixed 30–70 kg N ha^–1 by N₂ fixation, depending on the soil N supply and the length of the growing period of the CC. Nitrogen concentration in the aboveground biomass of legume CC was much higher and the C : N ratio much lower than in the nonlegume oil radish CC. At the time of CC incorporation (wheat series) as well as at the end of the growing season (potato series), soil nitrate content did not differ between the nonlegume CC species and mixtures, whereas pure stands of legume CC showed slightly increased soil nitrate content. When the CC were incorporated in autumn (beginning of October) nitrate leaching increased, especially from leguminous CC. However, most of the N leached only into soil layers down to 1.50 m and was recovered more or less by the following winter wheat. When CC were incorporated in late winter (February) no increase in nitrate leaching was observed. In spring, N availability for winter wheat or potatoes was much greater after legumes and, after mixtures containing legumes, resulting in significantly higher N uptake and yields in both crops. In conclusion, autumn‐incorporated CC mixtures of legumes and nonlegumes accomplished both: reduced nitrate leaching and larger N availability to the succeeding crop. When the CC were incorporated in winter and a spring‐sown main crop followed even pure stands of legume CC were able to achieve both goals.     

施肥水平对冬小麦田土壤水分影响的模拟

在模拟精度验证基础上,应用WinEPIC模型模拟研究了黄土高原长武早塬地1957～2001年期间不同肥力水平下连作冬小麦田的土壤干燥化效应.结果表明:4种肥力处理下连作冬小麦逐月土壤有效含水量均呈现波动性降低趋势,平均每年分别减少8.6、8.6、11.1和13.7 mm,无肥和低肥与中肥和高肥处理间土壤有效含水量差异十分显著,但无肥和低肥处理间无明显差异;在模拟初期出现了土壤湿度逐年降低、土壤干层逐年加厚的干燥化过程,在连作第5～8年以后均出现了稳定的土壤干层,无肥和低肥处理土壤干层均分布于2～3 m土层,中肥和高肥肥处理分别分布于2～4 m和2～5 m土层,随肥力和作物产量水平的提高,土壤干层厚度增厚;4种肥力处理麦田生产年度耗水量接近且呈现波动性缓慢降低趋势,但前1～4年中肥和高肥处理麦田共计较无肥处理麦田多耗水91和203 mm,长武旱塬地麦田土壤水分承载力为1.422～2.405 t/hm2,相应的肥力水平为N45～90 kg/hm2和P 15～30 kg/hm2.     

Effect of subsoiling on soil properties and winter wheat grain yield

A 2‐year field experiment was carried out in loessal soil in a semi‐humid climate to explore the integrative influences of subsoiling on soil properties and winter wheat grain yield. Results showed that it was essential to deepen the plough pan in loessal soil. The sharply increased soil penetration resistance (>7 MPa) in plough pan under dry soil condition was especially harmful for plant growth. In rotary tillage treatment, the waterlogging conditions caused by shallow plough pan slightly produced macropores and preferential water flow. Significantly, higher grain yield was obtained in the subsoiling tillage treatment, increased by 21.9% in 2016 and 11.3% in 2017, respectively. Subsoiling tillage improved the resilience of winter wheat under adverse climate conditions. Subsoiling tillage should be popularized in loessal soil with shallow plough pan in semi‐humid climate. This study may provide valuable information on soil sustainable use and management in loessal soil.     

Applying dredged sediment improves soil salinity environment and winter wheat production

Sedimentation and soil salinization are of serious concern in the Yellow River Delta. This study explores novel applications of dredged sediment to improve soil salinity environment and winter wheat (Triticum aestivum) production. Filed trials consisted of a control and applications of sediment at 100 Mg/ha (S100) and 200 Mg/ha (S200) replicated randomly within two blocks. Wheat growth and yield were assessed along with measurements of soil properties. Results indicated that sediment application significantly improved wheat growth. Wheat economic yield for S100 and S200 was 35% and 73% more than for the control. We attributed the improved wheat growth and yield to the reduced soil electrical conductivity, which, in turn, was associated with increased soil macropores and hydraulic conductivity with the incorporation of sandy sediment into the clayey saline soil. This study reveals that incorporating dredged Yellow River sediment into the saline land is a feasible agricultural practice in the Yellow River Delta.     

红壤酸化及石灰改良影响冬小麦根际土壤钾的有效性

【目的】了解初始酸度对石灰改良红壤钾素有效性的效应,为酸化红壤改良提供依据和支撑。【方法】本试验以湖南祁阳典型的第四纪红土为基础,人为调节出土壤pH分别为4.0、4.5、4.8、5.2的土壤。每个酸度土壤的一半加石灰改良至pH 6.0 (石灰改良处理),另一半不变(酸化处理)。以该土壤进行了小麦盆栽试验。每个盆内放入一个尼龙网根袋,并添加供试红壤1.65 kg (根袋中加150 g)。小麦生长80天后收获,调查了小麦生物量和钾吸收量,测定比较了小麦根际和非根际土壤不同形态的钾含量变化。【结果】1)不同酸化土壤冬小麦生物量(地上部和根部)与初始pH显著正相关(P＜0.05),也与钾吸收量显著正相关(P＜0.05)。石灰改良处理冬小麦生物量均显著高于相应的酸化处理,也随初始pH升高而显著升高。2)不同酸化土壤冬小麦根际土壤速效钾随pH升高显著降低,非根际土壤的速效钾含量均显著高于相应的根际土壤(除pH 4.0外)。石灰改良处理根际土壤速效钾含量均显著低于相应的酸化处理,且非根际土壤显著高于对应根际土,非根际土壤速效钾含量随初始pH升高而显著下降。3)不同酸化土壤冬小麦根际土壤钾离子饱和度随pH升高而显著下降,非根际土壤钾离子饱和度则随pH升高呈增加趋势。石灰改良处理土壤各处理根际土钾离子饱和度均显著低于对应的非根际土,同时非根际土钾离子饱和度与酸化处理的变化趋势一致。4)不同酸化处理红壤冬小麦生物量与根际速效钾亏缺量呈极显著正相关(P＜0.01),冬小麦根际土壤速效钾亏缺率和冬小麦吸钾量及根际钾离子饱和度亏缺率均呈极显著正相关(P＜0.01);而石灰改良处理根际土壤速效钾亏缺率则与初始pH呈显著负相关(P＜0.05)。【结论】在本试验的pH范围内,酸化条件下,根际土壤速效钾含量随pH降低而升高,而冬小麦吸钾量及生物量均随pH升高而升高。表明酸化红壤影响冬小麦钾养分吸收的主导因素是土壤的酸度。施石灰降低了土壤的酸度,提高酸化红壤作物产量和吸钾量。红壤施用石灰校正酸化应在pH降到5.0之前进行。酸化红壤石灰改良后,还应注意适量补充钾肥。     

化肥减施对冬小麦土壤呼吸的影响

为探明化肥减施对冬小麦土壤呼吸特征的影响,在新疆农业科学院奇台麦类试验站进行田间试验,以当地常规施肥量(N5P3)为对照,设置化肥不同减施量处理(N4P2、N3P2、N3P1、N2P1、N1P1、N0P1、N3P0、N0P0),采用土壤碳通量测量系统LI-8100测定和分析氮、磷减施下冬小麦在灌浆期与成熟期的农田土壤呼...     

基于土壤参数的冬小麦产量预测模型

为了实现冬小麦的精细田间管理,研究了基于土壤参数的冬小麦产量预测模型。采用灰色理论对冬小麦土壤电导率 EC值,全氮含量,K+、NO3-以及土壤pH值等因子进行灰色关联度分析,结果表明土壤EC值与土壤全氮含量,K+以及土壤 pH 值的灰色关联度较高。在分析不同生长时期土壤 EC 值,全氮含量,K+、NO3-以及土壤pH值和产量间的相关系数的基础上,采用土壤EC值,全氮含量以及K+作为模型的输入,产量作为输出,建立了冬小麦产量预测BP神经网络（BPNN）模型;采用土壤EC值,全氮含量,K+,灰色关联度作为输入,建立了小麦产量的模糊最小二乘支持向量机（FLSSVM）预测模型。建模结果表明,BPNN 模型的预测决定系数达0.8237,验证决定系数达0.7367;FLSSVM模型的预测决定系数达0.8625,验证决定系数达0.8003。BP神经网络以及FLSSVM预测模型的精度都较高,可以用来评估作物产量,为精细农业变量处方管理提供理论与技术支持。     

Zinc fractions in soil and uptake by wheat as affected by different preceding crops

Zinc (Zn) deficiency is widespread in alkaline and calcareous soils. Limited information is available on the effect of preceding crops on the distribution of Zn in soil solid phase. This field study was conducted to investigate the changes in Zn chemical forms in soil solid phase as affected by four preceding crops [Sunflower (Heilianthus annuus L. cv. Allstar), Sorghum (Sorghum bicolor L. cv. Speed Feed), Clover (Trifolium pratense L.) and Safflower (Carthamus tinctorius L. cv. Koseh-e-Isfahan)] in a calcareous soil. A control treatment with no preceding crop (fallow) was also used. Our results showed that the preceding crops increased Zn concentration in exchangeable fraction (EXCH-Zn), the organically bound zinc form (ORG-Zn) and zinc bound to iron and manganese oxides (FeMnOX-Zn) while decreased carbonates bound-zinc (CAR-Zn) and residual zinc forms (RES-Zn). However, the changes in Zn fractions were dependent on the preceding crop type. The EXCH-Zn and ORG-Zn pools can be considered labile pools that play significant roles in supplying Zn for plants. Among the preceding crops used in this experiment, clover (Clo) had the highest effect on transforming CAR-Zn form to EXCH-Zn and ORG-Zn labile forms and thus resulted in the highest Zn accumulation in tissues of the target wheat (Triticumaestivum L. cv. Back Cross). Although the changes in chemical forms of Zn in the soil solid phase are complex and dependent on various factors, our findings showed that the preceding crops significantly increased the concentration of Zn in exchangeable and organic matter pools and in turn resulted in higher uptake of Zn by the target wheat.     

玉米秸秆覆盖对麦田土壤温度和土壤蒸发的影响

研究了秸秆覆盖下的麦田土壤温度和土壤蒸发的动态变化规律。试验结果表明,玉米秸秆覆盖冬小麦田后,日最高地温比对照低,日最低地温比对照高,日振幅减小,温度变化较对照平缓;冬季具有提高土壤温度的作用,春季则有降低地温的作用。少覆盖处理冬季0～10 cm地温3年平均提高0.3℃/d,春季降低0.42℃/d;多覆盖处理冬季0～10 cm地温3年平均提高0.58℃/d,春季降低0.65℃/d;秸秆覆盖后有效地抑制了土壤蒸发,冬小麦生育期内,少覆盖处理比对照平均减少了21%,多覆盖减少了40.4%。覆盖处理春季的低温效应,推迟生育期3～7 d,加上后期的干热风,造成覆盖处理的冬小麦非正常成熟,影响了冬小麦的产量,少覆盖平均减产4.1%,多覆盖平均减产10.4%。     

长期不同施肥措施下潮土冬小麦农田基础地力演变分析

农田基础地力提升对于减施肥料和作物稳产高产有着重大现实意义,该文依托潮土长期定位试验,采用DSSAT(decision support system for agro-technology transfer)模型分析了长期不同施肥条件下冬小麦农田基础地力的演变规律及其影响因素。结果表明,不同施肥显著影响冬小麦的农田基础地力产量,18a连续施用氮磷钾化肥(NPK)、NPK配施有机肥(NPKM)、高量NPK配施有机肥(1.5NPKM)和NPK配施秸秆还田(NPKS)的农田基础地力均得到提升,其基础地力产量分别增加了721、1033、2108和1306kg/hm2,增长率分别为29.6%、42.4%、86.6%和53.7%,平均每年提高1.6%、2.4%、4.8%和3.0%,其中以1.5NPKM处理更能有效提高冬小麦农田基础地力产量。1991-2008年冬小麦的基础地力贡献率在36.5%～70.9%,各处理18a年均基础地力贡献率分别为42.5%、59.9%、58.9%和52.5%,大小顺序为NPKM>1.5NPKM>NPKS>NPK,说明有机肥或秸秆与化肥配施比单施化肥更能有效提高农田基础地力产量及地力贡献率。基础地力贡献率与土壤全钾、全磷含量无显著相关性,与土壤有机碳、全氮、碱解氮、有效磷、速效钾含量均达到了极显著相关,其中有机碳和全氮与基础地力贡献率相关度最高,说明土壤有机碳和全氮是潮土区基础地力的主要影响因素,是潮土区基础地力的主要评价指标。     

Improvement of wheat and maize crops by inoculating Aspergillus spp. in alkaline soil fertilized with rock phosphate

Aspergillus tubingensis and A. niger were isolated from the landfills of rock phosphate mines and tested for their efficacy to solubilize rock phosphate (RP), and improve plant growth and phosphate (P) uptake by plants grown in soil amended with RP. The results showed that they effectively solubilized RP in Pikovskaya's (PKV) liquid medium and released significantly higher amounts of P into the medium. A. tubingensis solubilized and released 380.8 μg P mL^?1, A. niger showed better efficiency and produced 403.8 μg P mL^?1. Field experiments with two consecutive crops in alkaline agricultural soil showed that inoculation of these fungi along with RP fertilization significantly increased yield and nutrient uptake of wheat and maize plants compared with control soil. P uptake by wheat and maize plants and the available P increased significantly in the RP-amended soil inoculated with fungi compared with control. These results suggest that the fertilizer value of RP can be increased, especially in alkaline soils, by inoculating P-solubilizing fungi.     

不同施肥条件下小麦田土壤呼吸特征研究

土壤呼吸是碳循环中的重要过程,为了解不同施肥措施对土壤呼吸过程的影响,在潮土小麦生长季研究了土壤呼吸特征.结果表明,土壤呼吸具有明显的昼夜变化和季节变化特征;土壤呼吸和土壤温度呈指数变化关系;有机肥和秸秆还田在生长后期显著增加了土壤呼吸速率,而仅仅NPK配施,减小了土壤呼吸速率.     

轮耕对土壤物理性状和冬小麦产量的影响

针对华北地区土壤连续单一耕作存在的主要问题,进行了土壤轮耕效应的研究。试验选择冬小麦夏玉米玉两熟区连续5 a免耕田,设置免耕、翻耕和旋耕3种轮耕处理（即免耕一免耕,免耕一翻耕和免耕一旋耕）,冬小麦播种前进行耕作处理。研究结果表明：多年免耕后进行土壤耕作（翻耕、旋耕）可以显著降低土壤体积质量;旋耕显著降低0～10 cm土壤体积质量,翻耕则降低0～20 cm体积质量;随时间变化各处理土壤体积质量差异逐渐降低。翻耕、旋耕均显著增加了0～10 cm土壤总孔隙,同时翻耕显著增加了10～20 cm土壤总孔隙;翻耕、旋耕显著提高了5～10 cm毛管孔隙。0～10 cm土壤饱和导水率表现为旋耕＞翻耕＞免耕,翻耕、旋耕在5%水平上显著高于免耕;10～20、20～30 cm土层均表现为翻耕＞旋耕＞免耕,且10～20 cm翻耕5%水平上显著高于免耕;饱和导水率与体积质量呈显著线性负相关。翻耕、旋耕有效穗数与免耕相比分别提高了24.1%、22.3%;冬小麦的实际产量表现为：旋耕＞翻耕＞免耕,翻耕、旋耕分别比免耕增产11.8%、16.9%。总之,长期免耕后进行土壤耕作有利于改善土壤物理性状,提高作物产量。     

冬小麦物候期对土壤水分胁迫的响应机制与模拟

作物模型在农业生产管理和决策中发挥着重要作用,而物候期模拟是作物模型正确模拟作物生长发育和产量形成过程的基础。作物模型模拟物候发育的常用算法一般是基于积温的计算,同时也考虑光周期和春化作用的影响,但是水分胁迫对物候发育的次级影响却较少被考虑在内。该研究以连续2季(2013-2014和2014-2015)的遮雨棚下土柱试验和连续3季(2012-2013、2013-2014和2014-2015)的遮雨棚下大田试验数据和前人研究成果为基础提出了冬小麦物候期对水分胁迫的响应机制理论假设,并以土壤相对有效含水率为水分胁迫指标校正冬小麦物候期水分胁迫响应函数。该研究以2014-2015生长季土柱试验各处理试验数据来建立冬小麦物候期水分胁迫响应函数,确定发育加速点A、发育减速点D和发育停止点S所对应的相对有效含水率值分别为0.30、0.10和0。结果发现拔节期和开花期模拟值和观测值之间的均方根误差(root mean square error,RMSE)分别为0.8和1.7 d,绝对相对误差(absolute relative error,ARE)分别低于0.68%和2.09%。然后用2013-2014生长季土柱试验各处理数据进行验证,结果发现拔节期和开花期模拟值和观测值之间的RMSE分别约为0.9和1.1 d,ARE分别在1.37%和1.68%以下。最后再用3年独立大田试验数据对上述修正后的冬小麦物候期算法进行验证,结果发现开花期和成熟期的模拟值与观测值之间的RMSE分别约为2.4和2.0 d,ARE分别低于4.21%和2.67%;与DSSAT-CERES-Wheat模型的模拟结果进行比较,发现修正算法能反映出水分胁迫对冬小麦物候期造成的差异(有提前也有推迟),而DSSAT-CERES-Wheat模型无法体现这种差异,且开花期和成熟期的模拟值与观测值之间的RMSE分别约为4.0和5.5 d,误差最大分别为8和6 d。这表明校正后的冬小麦物候期算法模拟精度得到了较大提高,能在一定程度上描述和量化水分胁迫对冬小麦物候期的影响机制,可用来模拟不同水分胁迫条件下不同品种冬小麦的物候期。     

滴灌条件下冬小麦田间土壤蒸发的测定和模拟

田间蒸发蒸腾总量(ETa)及其各分量的变化过程是农田水分利用与管理的主要依据。该文采用微型蒸发器(micro-lysimeters,MLS)对不同滴灌制度及覆盖处理下冬小麦田间土壤蒸发(Es)进行测定及评价。研究结果表明,滴灌条件下,采用内径10 cm,高度15 cm的MLS,在无降雨时每5 d换土能满足田间Es测定的精度要求(误差5%);滴灌条件下覆盖处理Es和Es/ETa均显著低于不覆盖处理,各处理的Es均值在0.98~1.30 mm/d之间,Es/ETa在33.0%~44.5%之间。此外,构建了基于灌水后天数(Dai)为自变量的Es简易估算模型,可在不获取表层土壤含水率的情况下,实现对滴灌条件下土壤蒸发较为精准的估算。该研究所建立的Es估算模型提供了滴灌农田Es的一种量化方法,确定的Es占ETa比例及其受覆盖等农艺措施的影响可为相关农业水管理实践提供科学指导。     

秸秆还田方式对农田土壤结构及冬小麦产量的影响

为探索一种能够充分发挥秸秆改良土壤结构和提高作物产量作用的秸秆还田措施, 通过2 a小区试验, 以传统的秸秆还田方式[长秸秆(50 mm)覆盖或翻压还田, CK1、CK2]作为对照, 对比研究了粉碎、氨化秸秆以及与无机土壤改良剂(硫酸钙)混合翻压施用措施对农田土壤结构及冬小麦产量的影响。结果表明, 粉碎并氨化秸秆施入土壤后, 能显著(P<0.05)降低耕层(0~15 cm)土壤的容重, 增加土壤孔隙度, 但对耕层以下土壤容重及孔隙度改善效果不明显; 氨化秸秆施入土壤后较未氨化秸秆能显著(P<0.05)增加0~15 cm土壤中>0.25 mm土壤团聚体含量, 粉碎并氨化秸秆能显著(P<0.05)降低土壤团聚体分形维数, 提高0~15 cm土壤平均重量直径和几何平均直径各项评价指标。此外, 冬小麦穗粒数、1 m2有效穗数、千粒重和地上部总干物质量与籽粒产量的相关系数分别为0.30(P>0.05)、0.76(P<0.01)、 0.89(P<0.01)和0.88(P<0.01), 提高冬小麦有效穗数或地上部总干物质量可能是增加作物产量的主要途径。粉碎并氨化秸秆还田较秸秆覆盖能显著(P<0.05)提高冬小麦有效穗数; 粉碎并氨化秸秆与无机土壤改良剂(硫酸钙)混合施用措施提高冬小麦产量效果最为显著, 在冬小麦2个生长季比长秸秆覆盖还田(CK1)分别增产11.12%和17.84%, 比长秸秆翻压还田(CK2)分别增产7.39%和16.58%, 是本试验最佳秸秆还田方式。该研究成果可为干旱、半干旱地区改良秸秆还田措施、提高作物产量提供理论依据。     

腐殖酸生物活性肥料对冬小麦生长及土壤微生物活性的影响

施用腐殖酸生物活性肥料对冬小麦生长和土壤微生物活性的试验结果表明,于等量无机养分水平下,施用腐殖酸生物活性肥料冬小麦群体发育平稳,改善植株性状明显,增强抗逆性能。与施用无机复混肥和习惯施肥处理相比,施用腐殖酸生物活性肥料,冬小麦穗长分别增加0.4和0.5cm,旗叶面积分别增加0.7和1.1cm2,次生根条数分别增加1.3和2.2条。产量构成因素中有效穗数,穗粒数和千粒重施用生物活性肥处理也明显高于无机复混肥和习惯施肥,其产量分别增加9.0％和15.2％,差异达显著水平。同时腐殖酸生物活性肥料能够促进土壤有益微生物繁衍,使土壤微生物数量明显增加,提高土壤脲酶、蔗糖酶、磷酸酶和过氧化氢酶活性,对提高肥效,增强土壤肥力,改善作物营养环境有一定作用。