西吉县聂家河坝窖池田联网补灌模式与集雨节水抗旱途径

介绍了宁夏西吉县聂家河流域实施的“坝窖池田”联网补灌模式及其效益。总结提出的农业集雨节水抗旱途径是大力实施淤地坝工程,拦截集蓄降水,济缺水之困,发展种养业;开挖大口井和土圆井,开发浅层地下水;修建薄壁水泥窖,充分利用天然降水资源;大力实施坡改梯工程,使降水就地拦蓄利用;大力实施科技入户工程,在节水上下功夫。     

香椿芽采后某些生理指标的变化

０℃下，香椿芽采后的呼吸强度很快下降；在其贮藏过程中，总叶绿素（ＴＣＨＬ）、叶绿素ａ（ＣＨＬａ）、叶绿素ｂ（ＣＨＬｂ）和Ｖｃ含量明显减少，过氧化物酶ＰＯＤ活性显著增强。贮藏３０ｄ，总叶绿素含量减少３８．９％，Ｖｃ减少９５．４％，ＰＯＤ活性提高４．５倍，无纤维化和落叶现象发生。     

不同降水年型节水小麦产量构成与效益分析

为筛选适宜北京地区小麦抗旱品种,同时为北京小麦节水栽培推广决策提供参考,2003—2006年间3个不同降水年型,在大兴区以28个小麦品种为材料,采用只浇冻水的节水措施,比较品种间产量构成因素和农艺性状等方面的差异性,并与常规灌溉管理进行比较分析。结果表明:(1)以产量水平为指标,参试品种间抗旱性存在显著差异。"中麦326"和"京农02-2"在平水年表现出较好的抗旱性;"北农9580"、"中麦12"、"京农04-133"和"京冬8"在枯水年表现出较好的抗旱性。(2)干旱条件下,小麦分蘖成穗过程受影响最大,分蘖成穗率可以作为小麦抗旱性筛选鉴定的较早期指标。(3)枯水年采取节水栽培比正常灌溉产量降低48.89%以上。效益综合分析结果认为,应用抗旱品种,即使在枯水年,北京地区小麦实施只浇冻水一水的节水栽培措施,也能取得明显的增效。     

南湾灌区续建配套与节水改造工程效益分析

南湾灌区续建配套与节水改造工程是国家专项资金资助项目。该工程的实施,使灌区内环境改善,节水明显,产生了显著的经济效益、社会效益和生态效益。     

河北省抗旱节水小麦生产现状及育种对策

简介了河北省抗旱节水小麦育种部分优异种质资源以及近年该省主栽抗旱节水小麦品种农艺性状及其筛选鉴定指标体系。并提出抗旱节水小麦育种策略     

施肥对珍贵树种榉树和闽楠幼树生长及生理的影响

开展造林后珍贵树种闽楠和榉树幼树施肥试验,以筛选出两树种幼树施肥的最适肥料及施肥水平,为两种珍贵树种幼树养分管理提供科学依据和技术指导。采用随机区组设计,以造林2a的榉树、闽楠幼树为研究对象,选择华强复合肥A (N-P-K:15-15-15)、喜盈盈复合肥B (N-P-K:25-5-10)、喜悦大地复合肥C(N-P-K:30-5-5)、尿素D (总氮≥46.2%) 4种不同养分配比的肥料及3种氮含量(15,18,21 g/株)施肥水平,以不施肥为对照,测定不同施肥处理榉树、闽楠幼树的13个生长生理及养分指标,最后综合各项指标进行主成分分析评价。不同施肥处理下榉树和闽楠13个生长生理及养分含量指标变化差异显著(P<0.05);其中,榉树、闽楠幼树对于各施肥处理后的生长生理响应最佳效果均表现为复合肥>尿素>对照,且复合肥的氮含量均在中等量18 g/株时更有利于生长。榉树在华强复合肥A2处理下其生长生理表现均最好,其株高、地径净增长量、叶面积、叶片含水率、可溶性蛋白含量、叶片磷(P)含量,分别比CK高16.7%、54.1%、49.5%、14%、72.4%和24.2%。闽楠在B2处理下生长生理表现最好,株高、地径、冠幅净增长量、叶片含水率、硝酸还原酶活性、叶片氮(N)含量和叶片钾(K)含量,分别比CK高35.7%、47.3%、63.0%、2.5%、187.1%、18%和38.7%。榉树在华强复合肥A2处理下各主成分综合值之和最高,排第1;同样,闽楠在喜盈盈复合肥B2处理下,排第1。最后综合两树种的生长生理情况,在相同含氮量18 g/株时,施用华强复合肥(N-P-K:15-15-15)对促进造林后榉树幼树生长最佳;施用喜盈盈复合肥(N-P-K:25-5-10)对闽楠生长更有利。     

Diurnal Variations in Photosynthesis,Stomatal Conductance and Leaf Water Relation in Sorghum Grown with or without Silicon under Water Stress

Sorghum [Sorghum bicolor (L.) Moench] was grown hydroponically with or without 50 ppm silicon (Si), and exposed to water stress from 10 days after sowing (DAS). At 15 and 23 DAS, we measured dry weight and diurnal variations in photosynthetic rate (P _N), stomatal conductance (g _s), transpiration rate (T), leaf water potential (ψ _L), and water uptake rate (23 DAS only). The reduction in dry weight at 23 DAS caused by water stress was ameliorated by silicon. Under water stress, silicon-treated seedlings showed higher g _s, P _N, and T than untreated ones. ψ _L remained almost constant within treatments throughout the daytime. Water uptake rate was reduced by water stress, but the reduction was ameliorated by silicon. We conclude that silicon enhanced water uptake and g _s, improving water supply to the leaves. These effects of silicon occurred soon after exposure to water stress.     

PHOSPHORUS AND MANGANESE INTERACTIONS AND THEIR RELATIONSHIPS WITH ZINC IN CHELATOR-BUFFERED SOLUTION GROWN RUSSET BURBANK POTATO

Manganese (Mn)- and zinc (Zn)-driven antagonistic interactions with high available phosphorus (P) can result in negative impacts on potato cropping systems. Two chelator-buffered hydroponic experiments were conducted with Russet Burbank potato to elucidate P and Mn relationships and associated interactions with Zn. In both experiments, a P concentration decline in new shoots, old shoots, and roots resulted as solution Mn changed from deficient to sufficient followed by a P concentration rise as solution Mn changed to excessive concentrations. New and old shoot Zn concentrations generally increased with augmented solution Mn in the variable Mn experiment, but no significant changes were found in root Zn contents. Available Mn was observed to control plant P concentrations and to influence Zn uptake and translocation; thus, Mn has considerable impact on uptake and distribution of P and Zn and on P-Zn interactions in potato.     

Straw and biochar effects on soil properties and tomato seedling growth under different moisture levels

ABSTRACT

A greenhouse experiment was conducted to evaluate the effects of wheat straw and its biochar on tomato seedling growth and soil physicochemical properties under different moisture levels. Treatments included control (no amendments, CK), three biochar amendments (B1: 1%, B2: 3% and B3: 6% w/w) and three straw amendments (S1: 1%, S2: 3% and S3: 6% w/w), under two moisture levels (M1: 40% water holding capacity (WHC) and M2: 70% WHC). The straw and biochar had contrasting effects on soil physiochemical properties and physiology of tomato seedlings. The B1 treatment significantly increased the soil urease activity (15%) and decreased the activity of dehydrogenase and β glucosidase enzymes (67% and 56%), as compared to the S1 treatment, especially for the high moisture condition. Biochar significantly improved shoot and root dry weights, biomass and altered chlorophyll contents. Plant antioxidants, superoxide dismutase (SOD), Peroxidase (POD) activities and malondialdehyde (MDA) were significantly decreased in biochar treatments, however, an increasing trend was observed for straw treatments. The current findings suggest that application of high amount of biochar (6%) or low amount of straw (1%) would be a reasonable management practice in semi-arid regions to improve soil physiochemical properties and the physiology of tomato seedlings.     

Aluminum tolerances of two snapbean cultivars related to organic acid content evaluated by high‐performance liquid chromatography

High‐performance liquid chromatography (HPLC) was used to determine aluminum (Al)‐induced changes in organic acid (OA) concentrations of Al‐tolerant ‘Dade’ and Al‐sensitive ‘Romano’ snapbean cultivars. Two week old ‘Dade’ and ‘Romano’ snapbean were grown in 1/5‐strength Steinberg nutrient solution for 10 days and then subjected to 0, 2, 4, 6, and 8 mg L^‐1 Al treatments at pH 4.5 for an additional 3–15 days. Current studies confirmed earlier findings that the Dade cultivar was significantly more tolerant to Al than the Romano variety. Organic acid analyses were performed on extracts of root and leaf, and on stem exudates. The organic acids were separated on an ion exclusion column using a mobile phase of 0.01 N H₃PO₄. Individual OA were quantified with a variable wavelength detector operating at 210 nm. Aluminum stress tended to reduce the concentrations of citric, malonlc, malic, glycolic, fumaric, and acetic acids in the roots and increased the OA concentrations in stem exudates. In the presence or absence of Al stress, the Al tolerant Dade cultivar contained higher OA concentrations than did the Al‐sensitlve Romano. Aluminum stress reduced total OA levels in root extracts from Al‐sensltive Romano plants to a greater extent than in those of the Al‐tolerant Dade. Malic and citric acid concentrations were decreased more than those of the other organic acids examined. Results indicate that the Al‐tolerant Dade snapbean cultivar has a higher potential for Al‐chelation and detoxification than does the Al‐sensitive Romano. Hence, an Al‐chelation mechansism may be involved in differential Al tolerance within this species.