黄土塬区旱作农田长期定位施肥对冬小麦水分利用的影响

对长期定位施肥试验第22年度的测定数据进行了分析,探讨了旱地施肥对冬小麦水分利用的影响。试验结果表明,测定年份冬小麦的耗水深度受播种前雨季降雨入渗深度的影响位于地下200 cm左右。长期施肥单施磷肥处理,播种期土壤有效贮水量与不施肥的对照接近,而单施氮肥,氮磷配施和氮磷钾配施均显著低于对照;在施P2O5 90 kg/hm2配施氮肥或施N 90 kg/hm2配施磷肥,随着施氮量或施磷量从0增加到180 kg/hm2,播种期土壤有效贮水量均逐渐降低,但前者作物的土壤水分消耗表现出降低趋势,而后者表现出增加趋势。与对照相比,各施肥处理均提高了土壤有效底墒的利用率。氮磷配施比单施磷肥降低了土壤供水占作物耗水的比例,使得作物生长和产量的形成对当季降水的依赖性增加。与对照相比,氮磷配施及氮磷钾配施显著提高了冬小麦收获指数、产量和水分利用效率,而单施磷肥和氮肥使收获指数、产量和水分利用效率显著降低。施P2O5 90 kg/hm2的条件下,不同施氮量之间收获指数差异较小,而产量和水分利用效率均高于单施磷肥;施N 90 kg/hm2的条件下,不同施磷量作物的收获指数、产量和水分利用效率均得到提高。     

黄土塬区氮磷配施对冬小麦光合作用、产量形成及水分利用的影响

在黄土高塬沟壑区,研究了不同施肥条件对冬小麦各个生育期的叶面积指数、光合作用、干物质积累、产量形成以及水分利用的影响,结果表明:与对照相比,施肥后小麦叶面积指数和光合速率都显著提高,同化作用增强,平均产量提高了47.6%,水分利用效率提高了24.6%。不同的肥料配施对冬小麦的干物质积累、产量以及水分利用效率的影响顺序基本一致,即高氮高磷>高氮低磷>低氮低磷>低氮高磷,但方差分析表明,在这种氮磷配施方案中起作用的主要是氮肥,磷肥的贡献不大,且二者并没有产生明显的交互作用。     

黄土塬区氮磷配施对冬小麦光合作用、产量形成及水分利用的影响

在黄土高塬沟壑区,研究了不同施肥条件对冬小麦各个生育期的叶面积指数、光合作用、干物质积累、产量形成以及水分利用的影响,结果表明：与对照相比,施肥后小麦叶面积指数和光合速率都显著提高,同化作用增强,平均产量提高了47.6%,水分利用效率提高了24.6%。不同的肥料配施对冬小麦的干物质积累、产量以及水分利用效率的影响顺序基本一致,即高氮高磷〉高氮低磷〉低氮低磷〉低氮高磷,但方差分析表明,在这种氮磷配施方案中起作用的主要是氮肥,磷肥的贡献不大,且二者并没有产生明显的交互作用。     

施肥对提高旱地农田水分利用效率的机理

１９９１ ～１９９５ 年,在陇东半湿润易旱地区以冬小麦为供试作物,通过氮、磷、有机肥三因素试验从生态学角度探讨了施肥对提高水分利用效率的机理。结果表明,施肥,尤其是氮磷化肥配施,可明显促进冬小麦根系生长,扩大觅水空间;氮磷化肥配施具有时效互补性和功能互补性;与不施肥处理相比,施肥处理蒸散量仅提高了５.４ ％ ,而产量和水分利用效率却分别提高了９２.８ ％ 和７９.７ ％;施肥促进了冬小麦冠层发育,增加了蒸腾量,而减少了蒸发量,从而提高了腾／发比,使水分利用效率及水分生产力大幅度提高。     

海冰水灌溉对棉田水分及棉花产量的影响

采用海冰水（全盐含量为3‰）灌溉与井水灌溉对比,结合3种施肥措施：无机肥（传统施肥）、有机肥与无机肥配施、土壤调理剂与无机肥配施和不施肥处理,研究不同施肥条件下海冰水灌溉对土壤水分、棉花产量及水分利用效率的影响。结果表明：1）棉花整个生育期海冰水灌溉处理1m土层的土壤含水率均高于井水灌溉的处理,尤其在灌溉后0—40cm土层的土壤含水率差异显著,约为12个百分点。2）海冰水灌溉条件下,有机肥与无机肥配施、土壤调理剂与无机肥配施较传统无机肥处理均可显著提高盐碱地棉花籽棉产量,分别增产约10％、27％,井水灌溉处理也有相同的趋势,分别增产约12％、22％。3）无论井水或海冰水灌溉,有机肥与无机肥配施或土壤调理剂与无机肥配施均可显著提高棉花的水分利用效率,海冰水灌溉小区的棉花水分利用效率,两种施肥处理均高于传统无机肥处理,约为8％、30％。两种灌溉水源对棉花产量和水分利用效率均无显著影响。     

不同管理措施对黄土塬区农田土壤水分调控和硝态氮淋溶累积的影响

【目的】研究黄土区旱作农田不同施肥和覆盖处理对土壤水分与硝态氮淋溶的影响,以提高水肥利用效率,增加作物产量,为选取适宜于该区可持续生产的农田管理措施提供理论基础。【方法】选取渭北旱塬定位试验中不施肥对照、施氮磷化肥、氮磷化肥配施钾肥、氮磷化肥配施生物炭、氮磷化肥与休闲期地膜全覆盖、氮磷化肥与生育期地膜全覆盖和氮磷化肥与全年地膜全覆盖共7个处理。分析了不同处理连续耕作冬小麦15年后收获期剖面硝态氮累积和生长季内土壤剖面水分变化状况。【结果】与对照相比,施氮磷化肥处理显著增加了硝态氮在0—300 cm土层中的累积,累积量是对照的6.1倍。与施氮磷化肥相比,在氮磷化肥基础上生育期地膜全覆盖、配施生物炭、配施钾肥和全年地膜全覆盖处理显著减少了土壤硝态氮累积量,分别减少了78.7%、73.2%、66.0%和59.7%,氮磷化肥与休闲期地膜全覆盖土壤硝态氮含量较施氮磷化肥处理虽无显著差异,但硝态氮累积量也减少19.2%。与对照相比,施氮磷化肥处理对0—300 cm土层水分补给和消耗量无显著影响。与施氮磷化肥相比,氮磷化肥基础上配施钾肥和生物炭对土壤水分补给和消耗量也无显著影响,而施氮磷化肥基础上的休闲期地膜全覆盖、生育期地膜全覆盖和全年地膜全覆盖显著增加土壤水分补给量,其中只有氮磷化肥与休闲期地膜全覆盖处理显著增加了土壤水分消耗量。硝态氮在土壤中的累积受土壤水分运移影响,其在土壤中的累积量随着水分补给量的增加而增加。土壤水分运移能显著影响硝态氮在土壤剖面的分布,其结果是氮磷化肥与生育期地膜全覆盖和氮磷化肥配施生物炭处理硝态氮主要分布在0—20 cm土层,氮磷化肥配施钾肥和氮磷化肥与全年地膜全覆盖处理硝态氮主要分布在0—100 cm土层,而施氮磷化肥和氮磷化肥与休闲期地膜全覆盖处理硝态氮主要分布在0—200 cm土层,其中施氮磷化肥和氮磷化肥基础上配施钾肥、全年地膜全覆盖、休闲期地膜全覆盖4个处理出现硝态氮累积峰。【结论】不同农田管理措施通过对水分的调控减少硝态氮淋溶,进而提高氮素利用效率,其中在施氮磷化肥的基础上增加生育期地膜全覆盖能有效调控土壤水分运移和减少硝态氮淋溶累积,是旱塬区改善农田水肥状况,增加作物产量的适宜措施。     

施肥和地膜覆盖对黄土旱塬土壤理化性质和冬小麦产量的影响

【目的】研究黄土高原旱作农业区施肥等措施对耕层土壤理化性质和作物农艺性状的影响,为保持土壤适度生产力,选择适合黄土塬区可持续发展的新型增产措施提供理论基础。【方法】通过设在渭北旱塬的多年田间定位试验,选取不施肥空白对照、施氮磷肥、施氮磷钾肥、氮磷肥加生物炭、氮磷肥加生育期地膜半覆盖和氮磷肥加夏闲期地膜半覆盖共6个处理,所有处理均在冬小麦收获后和播种前进行翻耕。分析了不同处理耕层土壤理化性质、冬小麦产量及农艺指标。【结果】与对照相比,施氮磷肥显著提高了耕层土壤饱和导水率,降低耕层土壤紧实度,显著增加冬小麦生育期耗水量,提高水分利用效率和降雨利用效率,显著提高了耕层土壤中有机质、全氮、硝态氮、铵态氮、全磷、有效磷等养分的含量,连续三年提高冬小麦的产量均在一倍左右。与氮磷肥处理相比,增施钾肥处理增加了冬小麦拔节期耕层土壤紧实度,却显著降低了收获期土壤容重、增加了总孔隙度,并显著提高了水分利用效率,在一定程度上增加了耕层土壤全氮、有机质含量,使冬小麦的叶面积指数显著增加,连续三年冬小麦平均产量达4500 kg/hm2;增施生物炭处理耕层土壤容重降至最低为1.16 g/cm3,增加了土壤总孔隙度,导致饱和导水率最大为0.049 cm/min,提高了水分利用效率;耕层土壤中的有机质、全氮、全磷、有效磷的含量有一定增加,冬小麦的产量有所提升;施氮磷肥基础上的生育期地膜半覆盖与夏闲期地膜半覆盖,均显著降低了耕层土壤饱和导水率,增加了土壤紧实度,提高了冬小麦水分利用效率,耕层土壤中有机质、铵态氮、速效钾的含量有所增加,全磷含量降低,土壤pH下降,除去受灾年份,冬小麦平均产量在4700～4800 kg/hm2之间。【结论】与对照相比,长期施用氮磷化肥显著提高冬小麦的产量,却导致土壤pH下降。在施氮磷肥的基础上增施生物炭,可以显著改善土壤物理化学性质,增加冬小麦产量,但其经济投入过高。在施氮磷肥的基础上,增施钾肥与生育期地膜半覆盖,改善了耕层土壤养分状况,有一定的经济效益,是适宜黄土塬区的冬小麦增产措施。     

水氮调控对冬小麦根冠比和水分利用效率的影响研究

通过田间和桶栽试验研究了水、氮调控对冬小麦根冠比和水分利用效率的影响。田间试验结果显示,土壤水分条件对冬小麦根冠生长影响显著。当冬小麦生育期60 cm土层土壤水分维持在田间持水量的60%以上时,根冠比维持稳定状态,不随灌溉次数的增加而变化;当冬小T麦生育期60 cm土层土壤水分低于田间持水量的60%时,土壤越干旱,根冠比越大。桶栽试验结果显示,氮素水平对冬小麦根冠比影响显著,而水氮互作效应对根冠比影响不显著。在所有水分处理条件下,随着施氮量增加,冬小麦根量减少。施氮对冬小麦地上部分和地下部分的影响不同。在水分亏缺条件下,随着氮用量增加,冬小麦经济产量呈增加趋势,水分利用效率与施氮量存在明显正相关关系;而在充分灌溉条件下,产量随着施氮量的增加表现出先增加后降低的趋势,存在一个氮肥用量阈值。因此,水氮通过调控地上地下干物质分配而影响作物产量和水分利用效率,在水分供应受限制条件下,增施氮肥会降低根冠比,更利于地上干物质的积累和经济产量形成。田间试验和桶栽试验均表明,冬小麦根冠比与水分利用效率呈负相关,根冠比大不利于地上部分干物质的积累和作物产量的形成,导致水分利用效率降低。     

不同施肥水平下旱地冬小麦水分效应研究

本文在北京地区旱地条件下，开展了氮磷水平对土壤和冬小麦水分状况的研究，结果表明：施肥可提高冬小麦生育前期的土壤水势。随施肥水平提高，小麦对土壤水分的利用能力增强。施肥可以提高小麦土壤水分利用效率，但高、中肥之间差异不显著。提高施肥水平，小麦旗叶叶水势降低，饱和含水量增大，相对含水量减少，自然饱和亏增加。各施肥水平小麦叶片耐脱水能力大小依次为中肥＞对照＞高肥。播前土壤有效贮水４２９．３ｍｍ左右，生育     

根修剪对黄土旱塬冬小麦群体结构、土壤水分及产量形成的影响

通过田间试验研究了返青期不同程度根修剪处理对冬小麦群体结构、土壤水分及产量形成的影响.结果表明,不同程度根修剪处理均减少了小麦的群体数量,改善了群体结构,从而使得根修剪处理花期时的透光率显著大于对照.根修剪处理还使小麦对土壤水分的消耗显著减少,花期时根修剪处理小区的土壤含水量均显著高于对照.土壤水分的改善促进了小麦的生理活性,使根修剪处理小麦的花期光合速率均显著大于对照.成熟期时小剪根处理对籽粒产量没有显著影响,但由于显著减少了水分消耗,因此,提高了小麦的水分利用效率,大剪根处理虽然提高了小麦水分利用效率,但由于严重影响了成穗数,从而造成产量显著下降.研究表明,在旱地农业生产实践中,如果能采用适当农艺措施以减少冬小麦前期旺长对土壤水分的过度消耗,使更多水分留在花后利用,将对作物产量及水分利用效率的提高非常有利.     

低锌旱地土壤水分对小麦产量和锌利用的影响

【目的】西北旱地土壤有机质含量低,pH和碳酸钙含量高,导致土壤有效锌含量低,加之水分缺乏,不仅制约冬小麦生长和产量,还严重影响小麦锌的吸收利用。本研究选取西北旱地典型缺锌区,在土施锌肥的基础上,设置了2年的补充灌水田间试验,进一步研究水分对土壤锌有效性、 小麦生长、 产量以及锌和相关元素吸收利用的影响。【方法】田间试验于2010~2012年在陕西永寿县进行,采用裂区设计,锌肥为主处理,在不施锌与施锌(ZnSO4·7H2O)50 kg/hm2的基础上,设置在冬小麦关键生长期补充和不补充灌水2个副处理。在成熟期采集植株样品,测定了小麦产量、 生物量,各器官部位的锌及氮、 磷、 钾、 铁的含量; 采集0—40 cm土层土壤,测定了土壤有效性锌含量。【结果】在返青期、 孕穗期补灌20~30 mm水分对小麦产量、 土壤有效锌含量无显著影响,却有提高小麦各部位锌含量、 锌肥利用率的趋势,不施锌和施锌条件下,灌水比不灌水处理小麦籽粒锌含量分别提高3.8%~16.3%、 3.8%~13.1%,灌水使锌肥利用率提高21.2%~177.8%。灌水量和灌水时期的不同也影响锌在小麦各器官部位的分配与累积,第一季施锌和不施锌条件下,灌水比不灌水处理锌收获指数分别降低5.1%和2.0%,而第二季锌收获指数分别提高2.1%和2.7%。两季灌水对小麦籽粒中铁及大量元素氮磷钾含量的影响亦各不相同。【结论】在旱地缺锌土壤上,小麦生长关键期灌水对小麦产量、 土壤有效锌含量无显著影响,却有提高小麦各部分锌含量、 锌肥利用率的趋势,说明水肥结合对旱地石灰性土壤锌和锌肥有效性的影响应引起进一步重视,这对提高旱地缺锌地区作物和人体锌营养水平具有潜在意义。     

Crop Productivity and Nutrient Bioavailability in a Potato-Based Three-Year Rotation as Affected by Composted Pulp Fiber Residue Application and Supplemental Irrigation

The possibility of using composted pulp fiber residues (CPFR) in a potato rotation in eastern Canada was tested. Three rates of CPFR (0, 45, and 90 Mg C ha^?1) with or without supplementary irrigation were applied. Pea (Pisum sativum L.), corn (Zea mays L.), and potato (Solanum tuberosum L.) were cultivated in 2002, 2003, and 2004, respectively. Soil total carbon (C) and nitrogen (N), bulk density, and water-holding capacity were improved by CPFR. Pea and corn yields and total dry matter were increased using CPFR. Supplemental irrigation increased pea yield compared with the rain-fed system. Total tuber yield was increased by CPFR in the irrigated but not in the rain-fed system. The CPFR application increased plant-available phosphorus (P) and potassium (K) in all rotation crops. Nitrogen accumulation in all rotation crops except potato was increased by CPFR. The CPFR application successfully enhanced soil fertility and crop productivity without any adverse effects.     

Improving the performance of bread wheat genotypes by managing irrigation and nitrogen under semi-arid conditions

Wheat (Triticum aestivum L.) productivity is generally affected by water limitation and inadequate nitrogen supply especially under semi-arid environment. The current study was conducted to determine whether the crop yield and irrigation water use efficiency (IWUE) could be manipulated through alteration of nitrogen and irrigation application. To meet the desired objectives, a two-year field study was carried out in 2013–2014 and 2014–2015, in a split-split plot arrangement with three factors i) irrigation in main plots, ii) nitrogen in sub-plots, and iii) twenty genotypes in sub-sub plots on a sandy loam soil. The analysis of variance revealed that the wheat performance was affected by genotypes and alteration of irrigation and nitrogen application with respect to IWUE and final grain yield. IWUE under water stress conditions was observed 56% higher than normal irrigated. Much higher values of IWUE under water stress indicated that the existing optimum water requirements of the crop needs to be revaluated. The regression model indicated that addition of nitrogen and irrigation patterns along with morphological traits cannot explain variation in yield related traits more than 65% under semi-arid conditions. Therefore, for better crop yields in semi-arid environment, more physiological parameters should be considered in evaluation of yield.     

Integrating rainwater harvesting with supplemental irrigation into rain-fed spring wheat farming

A field experiment was conducted at the Haiyuan Experimental Station (36°34′N, 105°39′E), in a semiarid region of China, from 2000 to 2003 for rain-fed spring wheat (Triticum aestivum) production to maximize the utilization of low rainfall. This paper reports the two field cultivations of rainwater harvesting with a sowing in the furrow between film-covered ridges (SFFCR), and with a sowing in the holes on film-covered ridges (SHFCR). At the same time, the periods and indices of supplemental irrigation during the whole growth stage of rain-fed spring wheat were also studied. The periods of supplemental irrigation included the three-leaf stage (irrigated once), the elongation stage to flowering stage (irrigated twice), and the flowering stage to filling stage (irrigated once). The indices of supplemental irrigation during the whole growth stage of rain-fed spring wheat must reach over 59 and 40 mm in order to realize the 2250 and 2000 kg ha⁻¹ yield, respectively. This research also presented such a concept of efficient water saving supplemental irrigation, which was considered as a new index of water saving irrigation. The experimental result showed that the efficiency of water saving supplemental irrigation of field cultivation with SFFCR was 5.5–5.8%, and with SHFCR was 9.4–9.6%. The efficiency of water saving supplemental irrigation of field cultivation with SHFCR was improved by 40.4% in comparison with SFFCR. Consequently, in this region, the integration of rainwater harvesting and supplemental irrigation can play a crucial role in the improvement of rain-fed spring wheat yields and water use.     

补灌与施肥对甜菜干物质积累、产糖量及养分吸收的影响

通过研究甜菜在雨养条件下施肥和施肥后补灌对甜菜干物质积累、产量、产糖量和养分吸收的影响规律，可以为甜菜栽培中施肥和灌溉提供理论依据。试验在田间条件下，设置雨养无肥(对照)、雨养施肥、补灌施肥3个处理，大区试验设计，3次重复。结果表明：收获期补灌与雨养施肥处理相比显著提高了甜菜总干物质积累量和产糖量；补灌施肥、雨养施肥与无肥处理相比显著提高了地上部和总干物质积累量、产量、产糖率和产糖量；收获期补灌与雨养施肥处理相比显著降低了甜菜地下部、地上部氮吸收量和总氮、总钾吸收量，雨养施肥与无肥处理相比显著提高了总氮、总钾吸收量；收获期补灌与雨养施肥处理相比显著提高了甜菜地下部、地上部干物质积累量和总磷吸收量，雨养施肥与不施肥处理相比显著提高了地上部干物质积累量和总磷吸收量。综合分析认为，补灌与雨养施肥处理相比利于促进甜菜生长发育，提高产量、产糖量和磷吸收量，降低甜菜对氮、钾的吸收量，建议在5—6月发生季节性干旱时进行人工补灌。     

Double-Cropped Soybean and Wheat with Subsurface Drip Irrigation Supplemented by Treated Swine Wastewater

The wastewater from swine production facilities has been typically managed by treatment in anaerobic lagoons followed by land application. However, there have been considerable advances in superior treatment technologies. Wastewater from one of these technologies was effective for subsurface drip irrigation of bermudagrass. The objectives of this experiment were to assess accumulation of soil nitrogen and carbon along with grain yield, dry-matter accumulation, and plant nitrogen accumulation of soybean [Glycine max (L) Merr., cv.] and wheat [Triticum aestivum (L), cv.] when supplementally irrigated with treated swine effluent via subsurface drip irrigation (SDI). The soil series was Autryville loamy sand (loamy, siliceous, subactive, thermic Arenic Paleudults). Its low unsaturated hydraulic conductivity of 0.0017 ± 0.0023 mm h^?1 caused problems with water movement to either the soil surface or laterally to adjoining soybean and wheat roots. This condition contributed to complete crop failure in soybean in 2 years and generally poor yields of wheat. In a good rainfall year, the soybean yield was somewhat satisfactory and benefited from the supplemental irrigation. In that year, nonirrigated and irrigated soybean mean yields were 1.55 versus 1.98 Mg ha^?1, respectively. The mean yield of wheat was only 1.06 Mg ha^?1, and it was not affected by irrigation. The means for soil nitrogen and carbon in the 0- to 15-cm depth were 414 and 5,679 mg kg^?1, respectively, and they were not affected by the water treatments. Thus, neither soil conditions nor soybean/wheat production were greatly enhanced by the SDI system.     

限量单次灌溉对套作冬小麦和春玉米产量的影响

A field experiment was conducted during the 2002/2003 cropping season of winter wheat (Triticum aestivum) and spring maize (Zea mays) to evaluate the effect of limited single drip irrigation on the yield and water use of both crops under relay intercropping in a semi-arid area of northwestern China. A controlled 35 mm single irrigation, either early or late, was applied to each crop at a certain growth stage. Soil water, leaf area, final grain yield and yield components such as the thousand-grain weight, length of spike, fertile spikelet number, number of grains per spike, and grain weight per spike were measured, and water use efficiency and leaf area index were calculated for the irrigated and non-irrigated relay intercropping treatments and sole cropping controls. The results showed that yield, yield components, water use efficiency, and leaf area index in the relay intercropping treatments were affected by limited single drip irrigation during various growth stages of wheat and maize. The total yields in the relay intercropping treatment irrigated during the heading stage of wheat and the heading and anthesis stage of maize were the highest among all the treatments, followed by that irrigated during the anthesis stage of wheat and silking stage of maize;so was the water use efficiency. Significant differences occurred in most yield components between the irrigated and non-irrigated relay-intercropping treatments. The dynamics of the leaf area index in the relay-intercropped or solely cropped wheat and maize showed a type of single-peak pattern, whereas that of the relay intercropping treatments showed a type of double-peak pattern. Appropriately, limited single irrigation and controlled soil water content level could result in higher total yield, water use efficiency, and leaf area index, and improved yield components in relay intercropping. This practice saved the amount of water used for irrigation and also increased the yield. Therefore, heading stage of wheat and heading and anthesis stage of maize were suggested to be the optimum limited single irrigation time for relay-intercropped wheat and maize in the semi-arid area.     

施肥对旱作区新修梯田土壤理化性质及马铃薯产量的影响

探究施肥对旱作区新修梯田土壤理化性质和作物产量的影响,对中低产田地力提升具有重要意义。利用2019年设置在定西市安定区新修梯田的定位试验,分析不施肥(CK)、施氮磷钾肥(NPK)、氮磷钾肥配施有机肥(NPKM)、氮磷钾肥配施有机肥再增施土壤调理剂(NPKMF)对土壤理化性质和马铃薯产量的影响,以评价施肥对新修梯田土壤的培肥效果。结果表明,与不施肥(CK)相比,各施肥处理均降低了新修梯田挖方部位和填方部位的土壤容重,提高了土壤总孔隙度和田间持水量,增加了土壤有机质、碱解氮、有效磷和速效钾含量,挖方部部位和填方部位马铃薯产量分别提高21.79%～66.13%和24.91%～32.28%。与施氮磷钾肥相比,氮磷钾肥配施有机肥再增施土壤调理剂降低了挖方部位和填方部位的土壤容重,提高了土壤总孔隙度和田间持水量,且对挖方部位的改善效果更显著;但土壤有机质、有效磷和速效钾含量差异均不显著,挖方部部位和填方部位碱解氮含量分别显著提高9.98%和10.00%,马铃薯产量分别提高了36.40%和5.90%。综上可知,氮磷钾化肥配施有机肥再增施土壤调理剂可降低土壤容重,提高土壤总孔隙度和田间持水量,提升土壤养分含量,增加马铃薯产量,是旱作区新修梯田地力提升的有效措施。     

不同补灌次数对旱地高产小麦氮素运转及产量的影响

试验研究了不同补灌处理对旱地高产田小麦氮素运转和产量的影响.结果表明: 增加补灌次数和灌水量, 导致小麦籽粒蛋白质含量降低, 旱地CK处理籽粒蛋白质含量最高, 其成熟期积累量虽然比灌1水和2水的处理低, 但显著高于灌3水以上处理.适量补灌, 可提高籽粒产量, 提高氮素利用率.补灌次数和补灌量过多, 小麦贪青晚熟, 氮素转移量小, 氮素转移率亦大幅度降低, 对产量提高的贡献并不大, 且产量和产量构成因素中千粒重、穗粒数反而下降, 低于灌2水和3水处理.综合考虑产量和水分利用效率、蛋白质积累等因素, 在本旱地高产试验田, 拔节期、灌浆期2水补灌120 mm的W2处理是最经济高效的补灌方案.