轮间作系统对烤烟产量、品质和土壤养分的影响

选择贵州省黔南烟区有代表性的植烟土壤,采用烤烟单作和间作（烤烟∥红薯和烤烟∥花生）,并在同一地块上实施年内间作,年间就地轮作的新型种植系统,连续6年研究了该系统对烟叶产量、品质和土壤养分的影响。结果表明:年内间作,年间就地轮作系统单位面积烟叶产量和产值连续六年显著高于烤烟单作,产量和产值平均提高11.3%和20.4%,作物总产值显著提高,并显著降低青枯病发病率约11.0%,烟叶化学成分含量适中,比例协调。年内间作,年间就地轮作系统种植6年后对土壤全量养分无显著影响,但显著改善土壤有效养分含量,适时保证养分供应,与烤烟单作系统相比,更能保持适宜的土壤有效养分比例,促进烤烟均衡吸收养分。因此,年内间作,年间就地轮作系统有利于减轻烤烟连作障碍,是值得推广的新型烤烟种植系统。     

蒜棉、麦棉套作对土壤微生物数量及相关酶活性的影响

在大田生产条件下,以棉花单作为对照,设置蒜棉套作、麦棉套作处理,研究蒜棉套作与麦棉套作对棉田土壤微生物数量及酶活性的影响,以揭示蒜棉、麦棉套作棉田棉花高产原因。结果显示:与单作棉田相比,蒜棉套作与麦棉套作均有利于棉田土壤中细菌、放线菌的增殖,并抑制真菌的增殖,其中蒜棉套作效果更显著;蒜棉套作020 cm土层脲酶活性和蔗糖酶酶活性在整个生育期显著高于棉田单作,碱性磷酸酶活性除花铃期外也均显著高于单作,过氧化氢酶在苗期与吐絮期显著高于单作;麦棉套作020 cm土层脲酶活性和蔗糖酶酶活性亦在苗期、花铃期显高于单作,碱性磷酸酶活性在蕾期显著高于单作,过氧化氢酶在苗期与吐絮期显著高于单作。结论:蒜棉套作与麦棉套作能提高棉田土壤微生物中细菌和放线菌的数量,有效抑制棉田连作障碍的发生。蒜棉套作与麦棉套作能提高棉田土壤相关酶活性,对棉田健康土壤的培育有积极意义。     

Overcoming Fe deficiency in guava (Psidium guajava L.) by co-situs application of controlled release fertilizers

Abstract

Among micronutrient deficiencies, Fe deficiency is the most difficult nutritional disorder to prevent in the fruits of trees growing on calcareous soils. In this study, a pot experiment was carried out to evaluate the potential of co-situs application of controlled release fertilizers (CRF) in alleviating Fe deficiency and improving the growth of fruit trees growing on calcareous soil (pH 9.3). Guava (Psidium guajava L.) seedlings were used as test plants because of their sensitivity to Fe deficiency. Treatments consisted of the following: (1) broadcast application of readily soluble Fe, Zn, Cu, B and Mn fertilizers (Control) or (2) co-situs application of CRF containing N, P, K, Mg, Fe, Zn, B, Cu and Mn (Co-situs). For the Control treatment, CRF containing only N, P and K was used. Both treatments received the same amount of all nutrients. Plants were more chlorotic in young leaves under the Control treatment and the Fe content of young leaves was significantly (least significant difference [LSD_0.05]) higher under the Co-situs treatment. Dry matter production of shoots under the Co-situs treatment was 5.2-fold higher than under the Control treatment, and the total accumulations of macro and micronutrients were much higher under the Co-situs treatment than the Control treatment. Total accumulations of N, P, K, Ca and Mg were 5.0, 4.1, 9.6, 3.2 and 2.2-fold higher, respectively, under the Co-situs treatment compared with the Control treatment, and Fe, Zn, Cu and Mn accumulations were 3.2, 4.1, 6.0 and 3.7-fold higher, respectively. Iron deficiency in guava seedlings was successfully alleviated by the co-situs application of controlled fertilizer, proving the high potential of this method in alleviating Fe deficiency in fruit trees growing on calcareous soils.     

麦棉套种共生期不同土壤水分对冬小麦生理特性及产量与品质的影响

冬小麦、棉花套种共生期包括小麦灌浆期和棉花的苗期,这一时期对冬小麦生长及产量和品质形成具有重要意义。该文在3-1式和4-2式两种麦棉套种配置方式条件下,研究了麦棉共生期土壤水分条件对小麦生理特性以及产量和品质的影响。试验结果表明,土壤水分显著影响了小麦的光合蒸腾日变化动态。共生期较高的土壤水分不利于干物质向籽粒的运输和分配,其产量以70%土壤含水率处理最高。较低的土壤水分有利于小麦籽粒蛋白质和湿面筋含量以及沉降值的提高。3-1式小麦更容易受到土壤水分亏缺的抑制。     

Impact of organic‐manure combinations on the productivity and soil quality in different cropping systems in central India

In a field experiment, the effect of combination of different organic manures on the productivity of crops and soil quality were evaluated in deep vertisols of central India. Combinations of cattle dung manure (CDM), poultry manure (PM), and vermicompost (VC) vis‐à‐vis mineral fertilizers were tested in four cropping systems involving soybean (Glycine max L.), durum wheat (Triticum durum Desf.), mustard (Brassica juncea L.), chickpea (Cicer arietinum L.), and isabgol (Plantago ovata Forsk). The organic manures were applied based on the N‐equivalent basis and nutrient requirement of individual crop. The grain yields of durum wheat and isabgol were higher in the treatment that received a combination of CDM + VC + PM whereas in mustard, CDM + PM and in chickpea, CDM + VC recorded the higher yields. The yield levels in these organic‐manure combinations were similar to the yields obtained with mineral fertilizers. Among the cropping systems, soybean–durum wheat and among the nutrient sources, the combination of CDM + VC + PM recorded the highest total productivity. At the end of the 3‐year cropping cycle, application of organic manures improved the soil‐quality parameters viz., soil organic carbon (SOC), soil available nutrients (N, P, and K), soil enzymes (dehydrogenase and alkaline phosphatase), and microbial biomass C in the top 0–15 cm soil. Bulk density and mean weight diameter of the soil were not affected by the treatments. Among the cropping systems, soybean–durum wheat recorded the highest SOC and accumulated higher soil available N, P, and K. In conclusion, the study clearly demonstrated that the manures applied in different combinations improved the soil quality and produced the grain yields which are at par with mineral fertilizers.     

槟榔不同株行距间作香草兰对土壤养分和微生物的影响

为了揭示槟榔不同株行距间作香草兰对土壤微生物和土壤养分的影响,以生产上槟榔3个种植密度间作香草兰为处理,人工荫棚单作香草兰为对照,测定和分析土壤中微生物的数量和土壤养分的含量。结果表明,槟榔间作香草兰可显著提高土壤微生物的数量,改良土壤微生物群落中真菌、 细菌和放线菌的比例。槟榔株行距为2.0 m2.5 m（Tr2）的处理,土壤pH值及有机质、 全K、 碱解N、 速效P、 速效K、 交换性Ca、 有效Fe、 有效B含量均显著提高。Pearson积矩相关分析表明,土壤中各类微生物的数量与土壤养分含量之间存在着多种显著的相关关系。槟榔株行距为2.0 m2.5 m间作香草兰对土壤微生物数量及其比例与土壤养分含量具有良好的调节作用,且彼此具有显著相关性。     

间套作改善作物矿质营养的机理研究进展

【目的】合理的间套作能够改善作物的矿质营养。近年来国内外对间套作提高作物生产力、 改善作物矿质营养的机理研究越来越深入。本文分析了国内外不同间套作中作物根际养分动态及作物营养吸收变化,阐述了间套作改善作物矿质营养的可能机理。【主要进展】 1)根系分泌物中的铵态氮和氨基酸态氮作为作物的氮源; 根系分泌物能够诱导豆科作物固氮作用的增强,增加间套作系统中的氮营养; 2)根系分泌物中的有机酸类物质能够活化根际土壤中的磷、 铁、 钾等营养,将其转变为植物可以利用的营养; 3)根系分泌物或地上部的种间互作能诱导作物的根系构型和矿质营养吸收相关基因的表达发生变化,形成空间上的营养生态位互补,增强根系吸收矿质营养的能力,充分利用土壤营养资源; 4)丛枝菌根真菌与作物间形成的网络便于营养在作物之间的转移和吸收; 5)间套作能够改变土壤生物多样性(土壤动物和微生物),而土壤的生物多样性能够促进作物矿质养分的吸收。间套作中,由于微生物代谢功能的多样性,作物对微生物的选择和富集使得根际土壤功能微生物的种类和数量增多,提高了土壤中矿质营养的生物有效性; 6)间套作提高了土壤的酶(如脲酶,酸性磷酸酶和碱性磷酸酶)活性,促进了有机氮、 磷向无机氮、 磷的转化,提高了土壤无机氮、 磷的浓度。总之,根系分泌物、 根系构型变化、 土壤生物多样性、 土壤酶在作物的营养有效利用中发挥重要作用,其中根系分泌物是它们之间的纽带,介导了作物-作物、 作物-土壤、 作物-微生物之间的相互作用。【建议与展望】由于技术手段的限制及地下根际过程的复杂性,人们对于地下生物学过程的认识还远远不够。根系分泌物的原位定性与定量、 间套作中种间的识别和响应、 间套作对土壤生物多样性的影响及土壤生物多样性对作物生长的反馈、 间套作中功能微生物的筛选、 分离、 鉴定及应用都将成为研究的重点。     

旱地多熟间套作不同培肥方法对作物产量和土壤肥力的影响

通过设三季秸秆还田、三季秸秆＋冬绿肥还田、三季栏肥还田、冬绿肥还田及主施化肥为对照等5个处理，研究了山区旱地多熟间套作不同培肥方法的培肥效果，试验结果表明，各种培肥方法的培肥效果依次为三季栏肥还田〉三季秸秆〉冬绿肥还田〉三季秸秆还田〉冬绿肥还田〉对照。     

Characterization of the aroma-active compounds in pink guava (Psidium guajava, L.) by application of the aroma extract dilution analysis

The volatiles present in fresh, pink-fleshed Colombian guavas ( Psidium guajava, L.), variety regional rojo, were carefully isolated by solvent extraction followed by solvent-assisted flavor evaporation, and the aroma-active areas in the gas chromatogram were screened by application of the aroma extract dilution analysis. The results of the identification experiments in combination with the FD factors revealed 4-methoxy-2,5-dimethyl-3(2 H)-furanone, 4-hydroxy-2,5-dimethyl-3(2 H)-furanone, 3-sulfanylhexyl acetate, and 3-sulfanyl-1-hexanol followed by 3-hydroxy-4,5-dimethyl-2(5 H)-furanone, ( Z)-3-hexenal, trans-4,5-epoxy-( E)-2-decenal, cinnamyl alcohol, ethyl butanoate, hexanal, methional, and cinnamyl acetate as important aroma contributors. Enantioselective gas chromatography revealed an enantiomeric distribution close to the racemate in 3-sulfanylhexyl acetate as well as in 3-sulfanyl-1-hexanol. In addition, two fruity smelling diastereomeric methyl 2-hydroxy-3-methylpentanoates were identified as the ( R,S)- and the ( S,S)-isomers, whereas the ( S,R)- and ( R,R)-isomers were absent. Seven odorants were identified for the first time in guavas, among them 3-sulfanylhexyl acetate, 3-sulfanyl-1-hexanol, 3-hydroxy-4,5-dimethyl-2(5 H)-furanone, trans-4,5-epoxy-( E)-2-decenal, and methional were the most odor-active.     

滴灌定额对西瓜/棉花间作产量及水分生产效率的影响

该文将膜下滴灌灌水技术集成到西瓜/棉花间作系统中,探讨滴灌灌水定额15、22.5、37.5及30 mm处理（对照）对瓜棉间作作物生长、产量、水分生产效率及经济效益的影响。结果表明：灌水定额37.5 mm西瓜生育前期主蔓最长,棉花全生育期株高最高,灌水定额22.5 mm西瓜生育中后期主蔓长逐渐变大,灌水定额15 mm全生育期西瓜主蔓长和棉花株高值均最小;间作群体叶面积指数呈双峰曲线变化,共生期内灌水量越大,LAI均值越大,非共生期各水分处理LAI均值无显著差异;灌水定额22.5 mm棉花成铃数最多、最终脱落率最小（59.6%）,灌水定额37.5 mm最终脱落率最高（62.3%）;灌水定额22.5 mm显著提高了瓜棉间作产量、水分生产效率、经济效益,西瓜产量为59697.0 kg/hm2,棉花产量为4851.2 kg/hm2,水分生产率为28.20元/m3,总产出值高达163054.8元/hm2。综上可见,该地区瓜棉间作适宜的灌水定额为22.5 mm,全生育期共灌水7次,可实现瓜棉间作高产和水分高效利用的统一,能为该地区瓜棉间作系统科学使用滴灌灌水技术提供参考。     

覆盖与间作对亚热带丘陵幼龄茶园土壤环境和生产的影响

以常规管理茶园(清耕茶园)为对照,通过连续4a大田对比试验,研究了稻草覆盖与间作白三叶草对亚热带丘陵幼龄茶园土壤环境及茶叶品质、产量的影响。研究结果表明：两种生物措施均降低了土壤容重,增加了土壤有机质含量,影响了土壤养分的供应状况,提高了土壤关键层次(0～20 cm)和关键时期(4～6月)的水分含量,获得了不同观察时刻、不同深度土壤温度的多种调控效果,延缓和缩短了高温和干旱时间,促进了茶树生长,改善了茶叶品质,显著增加了茶叶产量,其名优绿茶酚氨比分别下降了0.68%和28.14%,产量提高了26.19%和32.65%,间作白三叶草的效果更好。     

玉米/大豆不同间作模式下土面蒸发规律试验研究

为了准确估算间作农田土壤水分动态变化过程,制定合理的灌溉制度,该文采用微型蒸渗仪测定了玉米/大豆不同间作模式下不同位置处的土面蒸发量,分析了相对土面蒸发强度与表层土壤含水率的关系以及相对土面蒸发强度与叶面积指数的关系.结果表明:玉米/大豆间作模式下,不同位置处的土面蒸发量存在差异,2:3间作的累积蒸发量大于1:3间作;相对土面蒸发强度与表层土壤含水率呈指数递增关系,与叶面积指数呈指数递减关系.     

Influence of Zn nutrition on the productivity,grain quality and grain biofortification of wheat under conventional and conservation rice–wheat cropping systems

ABSTRACT

This study was conducted to evaluate influence of zinc (Zn) application on productivity, grain biofortification and grain quality of wheat planted under plough tillage (PT) and zero tillage (ZT) systems. Zn was delivered as soil application (10 kg ha^?1), foliage spray (0.025 M) and seed priming (0.5 M) in wheat planted under PT and ZT systems. ZT had higher total soil porosity, total soil organic matter, soil organic carbon and soil microbial biomass carbon than PT. Zn application, by either method, improved grain yield, grain Zn and grain quality in both tillage systems. The grain Zn concentration was 72% and 59% higher with soil-applied Zn in ZT wheat during 2016–2017 and 2017–2018, respectively, compared with no Zn. However, Zn seed priming was the most effective in improving wheat grain yield in both tillage systems. Foliage and Zn soil application were better in improving the indices of Zn use efficiency of Zn. In conclusion, Zn seed priming was the most effective method in improving the wheat grain yield, whereas soil Zn application in ZT and foliar applications in PT were the most effective for grain Zn biofortification. However, Zn soil application was the most cost-effective method of Zn application.     

Effects of intercropping and drought on soil aggregation and associated organic carbon and nitrogen

Drought has significant effects on soil physicochemical properties and thereby crop productivity. Intercropping is a traditional agricultural practice with a good ecological effect and can improve soil structure. However, the effects of intercropping on soil aggregate distribution and associated organic carbon (OC) and nitrogen (N) compared with monoculture under drought remains unclear. Therefore, a two-year controlled rainfall field (i.e., 30–40 days of 100% rainfall reduction during crop growth) was carried out to examine the effects of intercropping and short-term drought on soil aggregate stability and associated OC and N in Northeast China. Results showed that soil OC and N were predominant in macroaggregates (2–0.25 mm), accounting for 39%–51% of SOC, 36%–51% of N at 0–10 cm depth, and 44%–67% of SOC, 43%–66% of N at 10–20 cm depth. After 2 years of a rainfall reduction treatment, large macroaggregates (>2 mm) increased by 84.7% at 0–10 cm and the aggregate stability improved. There was no difference in the mass of aggregates between monoculture and intercropping, but short-term drought increased >0.25 mm aggregates and stability in intercropping soil at 0–10 cm depth. Moreover, drought significantly increased bulk soil OC in 10–20 cm but decreased the OC and N concentrations in large macroaggregates and silt + clay fractions (<0.053 mm) in 0–10 cm. Compared with the monoculture, intercropping enhanced OC and N concentrations in aggregates, and decreased soil C/N ratio. Therefore, these findings provide insights into how intercropping and short-term drought interactively influence soil aggregation, and C and N processes.     

木醋液土壤灌溉对土壤养分、番茄产量及品质的影响

采用田间小区试验,研究了木醋液不同灌溉量对土壤养分、盐碱和番茄产量及品质的影响。结果表明,土壤灌溉木醋液可提高土壤碱解氮、速效钾、有效磷含量,且使用量越大,效果越明显,其中有效磷含量增加最为显著,与对照相比可提高9.27%~25.51%;木醋液也可提高土壤有机质及全盐含量,但与对照相比差异不显著;木醋液还可降低土壤p H值,与对照相比可降低0.14~0.27个单位。木醋液低[2.25 t/(次·hm~2)]、中[4.50 t/(次·hm~2)]用量能显著提高番茄株高、增加产量,其中低用量效果最好,与对照相比可提高株高10.53%,增加产量11.52%;高用量[7.50 t/(次·hm~2)]对番茄生长具有一定抑制作用。木醋液可提高番茄可溶性糖含量5.27%~10.28%,提高Vc含量3.46%~17.15%,降低硝酸盐含量4.25%~15.33%,对有机酸含量影响不明显。综上所述,建议设施土壤番茄季木醋液灌溉量为2.25~4.50 t/(次·hm~2)为宜。     

施氮量对玉米/大豆套作系统土壤微生物数量及土壤酶活性的影响

为揭示玉米/大豆套作体系下土壤氮素转换的调控机理和根际微生态效应,以种植模式为主因素[设玉米单作(MM)、大豆单作(SS)和玉米/大豆套作(IMS)3种处理],以玉米、大豆施氮总量(玉米、大豆施氮比例为3∶1)为副因素[设不施氮(NN,0 kg?hm~(-2))、减量施氮(RN,180 kg?hm~(-2))和常量施氮(CN,240 kg?hm~(-2))3个处理],研究了玉米/大豆套作系统下不同施氮量对作物根际土壤微生物数量及土壤酶活性的影响。结果表明:与相应单作相比,套作下玉米根际土壤真菌、放线菌数量分别提高25.37%和8.79%;套作大豆根际土壤真菌、放线菌、固氮菌数量高于单作大豆;套作玉米根际土壤蛋白酶、脲酶活性和套作大豆根际土壤蛋白酶活性均显著升高。各施氮水平间,减量施氮下玉米、大豆根际土壤真菌数量较常量施氮和不施氮均有所提高;施氮提高了玉米、大豆根际土壤放线菌数量;大豆根际土壤固氮菌数量以减量施氮最高,比不施氮和常量施氮高17.78%和5.67%;玉米根际土壤蛋白酶活性、脲酶活性和大豆根际土壤脲酶活性均以减量施氮为最高。适宜的施氮量不仅能增加玉米/大豆套作土壤中真菌、放线菌、固氮菌的数量,还能提高土壤蛋白酶、脲酶活性,调节土壤氮素的转化,促进玉米/大豆对土壤中氮素的吸收,实现节能增效。     

土壤调理剂对日光温室土壤理化性质和蔬菜产量、品质的影响

试验研究了土壤调理剂对日光温室土壤理化性质和蔬菜产量、品质的影响。结果表明,施用土壤调理剂能够明显改善土壤结构,增强土壤保水能力,与对照相比,施用2次调理剂后土壤容重降低6.36%,土壤总孔隙度增加4.97%,田间持水量增加6.75%,渗透系数提高46.28%;调理剂还能增加土壤养分含量,提高土壤保肥能力;调理剂能够提高蔬菜的产量和品质,对番茄品质的改善效果尤为明显;调理剂与秸秆配合施用效果更佳。     

长期施用不同肥料对小麦玉米间作产量、氮吸收利用和土壤硝态氮累积的影响

对连续14年施用不同肥料后,春小麦.春玉米间作下,土壤硝态氮的累积和分布,作物产量及对氮素的吸收利用进行了研究。结果表明,在施农家肥120t.hm2(M)、绿肥45t.hm2(G)、秸杆10.5t.hm2(S)、N375kg.hm2(N)、农家肥60t.hm2+N187.5kg.hm2[1/2(M+N)]、绿肥22.5t.hm2+N187.5kg.hm2[1/2(G+N)]、秸杆5.25t.hm2+N187.5kg.hm2[1/2(S+N)]和CK等8个处理中,土壤剖面硝态氮的累积和分布以N处理最高,地上部N浓度和吸N量以N、1/2(M+N)和1/2(G+N)处理较高,但3处理间无明显差别。间作小麦子粒产量和生物学产量以M、G、1/2(M+N)和1/2(G+N)等处理较高,间作玉米子粒产量和生物学产量以1/2(G+N)、N、G和1/2(M+N)等处理较高。氮肥利用率以1/2(S+N)处理最高,1/2(M+N)和1/2(G+N)低于1/2(S+N)、S和N处理,但高于M、G处理。说明氮肥与农家肥或绿肥配合施用,既能增加作物产量,提高氮素吸收利用,又可减少土壤中硝态氮的累积。     

Diffuse reflectance spectroscopy (DRS) for rapid soil testing and soil quality assessment in smallholder farms

Rapid soil testing and soil quality assessment are essential to address soil degradation and low farm incomes in smallholder farms. With the objective of testing diffuse reflectance spectroscopy (DRS) to rapidly assess soil chemical properties, nutrient content and a soil quality index (SQI), samples of surface soil were collected from 1113 smallholder farms in seven districts in Bundelkhand region of Uttar Pradesh, India. A minimum dataset (MDS) approach was followed to estimate SQI using the three chemical parameters of soil pH, electrical conductivity (EC) and soil organic carbon (SOC), and 11 different soil nutrients. Principal component and correlation analyses showed that soil pH, SOC content and three available nutrients − copper (Cu), iron (Fe) and sulphur (S) − may constitute the MDS. Estimated SQI values showed strong positive correlation with crop yields. Results of chemometric modelling showed that the DRS approach could yield the coefficient of determination (R²) values in the validation datasets ranging from 0.79 to 0.94 for exchangeable calcium (Ca) followed by 0.67–0.88 for exchangeable potassium (K), 0.52–0.86 for SOC and 0.53–0.81 for available boron (B) content. Except in one district, the DRS approach could be used to estimate SQI values with R² values in the range of 0.63–0.81; an R² value of 0.71 was obtained in the pooled dataset. We also estimated the three-tier soil test crop response (STCR) ratings to compare DRS and wet chemistry soil testing approaches. Similar STCR ratings were obtained for both these approaches in more than 86% of the samples. Parameters for which both the methods yielded similar ratings in more than 80% of the samples were EC (>98%), pH and exchangeable Ca (>81%) and available B (>89%). With similar ratings, these results suggest that the DRS approach may safely be used for farmers' fields, replacing the traditional wet analysis approach of soil testing.