重庆柑橘园土壤微量营养元素养分状况分析

【目的】了解重庆柑橘园土壤微量营养元素养分状况。【方法】在重庆15个柑橘主产县(区)选取567个代表性柑橘园采集土壤样本进行测定分析。【结果】果园土壤pH值变幅pH 4.1～8.7,但仅有20.99%的土壤pH适宜柑橘生长(pH值5.5～6.5),53.62%的土样pH高于6.5,并有35.63%的土样pH高于7.5。土壤有机质匮乏,有机质偏低或缺乏比例达68.79%。土壤有效Fe、Mn、Zn、Cu、B的平均含量分别为40.91 mg·kg~(-1)、15.69 mg·kg~(-1)、1.39 mg·kg~(-1)、1.06 mg·kg~(-1)、0.37mg·kg~(-1),土壤有效Fe、Mn、Zn、Cu、B含量处于适宜及以上水平的比例分别占77.08%、0.18%、53.62%、73.02%、23.28%;总体上土壤有效Fe、Cu含量水平较高,有效Zn、B含量较低,有效Mn含量缺乏。【结论】柑橘生产上应注意调节土壤pH值,结合叶片营养诊断适量补充含Mn、B、Zn的微量元素肥料或有机肥。     

环渤海湾和黄土高原‘富士’苹果园土壤养分与果实矿质元素关系的多变量分析

探讨中国环渤海湾和黄土高原两大苹果产区土壤养分对‘富士’苹果果实矿质元素含量的影响及相互关系,为两大苹果产区提高果实矿质元素含量的果园合理施肥等提供理论依据。2010—2011年分别在中国环渤海湾和黄土高原两大苹果产区各选择22个县,每县3个果园,共计132个乔砧‘富士’苹果园,对每个果园的土壤养分和果实矿质元素含量进行调查和分析,比较两大产区土壤养分、果实矿质元素含量的差异,应用偏最小二乘回归方法筛选不同产区影响果实矿质元素含量的主要土壤养分因子,线性规划求解优质果实矿质营养丰富的土壤养分含量优化方案。结果表明:环渤海湾产区的土壤碱解氮、有效磷、钙、铁和锌含量极显著高于黄土高原产区,而土壤pH和有效钾含量显著低于黄土高原产区;环渤海湾产区‘富士’果实氮、磷含量显著高于黄土高原区,而钙、铁和锌含量则显著低于黄土高原产区。黄土高原产区土壤有效铁、环渤海湾产区土壤有效硼含量分别与果实中的铁、硼呈显著和极显著相关。环渤海湾产区影响果实钙含量的主要土壤养分因子的大小顺序为土壤有机质、全氮、有效锌、有效硼、有效铁和有效钾,土壤有效锌对果实钙有最大的正效应系数,而土壤有效硼和全氮负效应系数较大;黄土高原产区对果实钙含量影响的主要土壤养分因子的大小顺序为土壤有效磷、有效锌、有机质、有效铁和有效钾,土壤有效锌、铁对果实钙含量有较大的正效应系数。线性规划求解出两大苹果产区果实矿质元素含量丰富的土壤养分优化方案。环渤海湾苹果产区增加果实钙含量的主要土壤养分管理措施为降低土壤全氮、碱解氮含量,提高土壤有效钾、铁、锌含量,维持较高的土壤有机质含量(17.7 g·kg~(-1)以上);黄土高原产区则为提高土壤有机质、有效锌含量,降低土壤全氮、碱解氮含量,保持适宜的土壤有效磷、钾含量。     

赣南脐橙园种植区和背景区不同土层养分丰缺状况

【目的】探究赣南脐橙产区土壤基本养分含量及其变化趋势,探讨限制脐橙生产的关键限制因子,为合理施肥提供科学依据。【方法】于2018年在该区域脐橙主产区选取105个代表性果园,分别采集种植区和背景区0～20 cm和20～40 cm土层样品进行测定分析。【结果】与背景区相比,种植区土壤pH值呈降低的趋势,其中20～40 cm土层pH值显著低于背景区。赣南脐橙园土壤有机质含量(w,后同)范围介于3.1～45.0 g·kg-1,种植区和背景区超出适宜水平的比例分别占51%和69%,其中种植区0～20 cm土层有机质含量显著高于背景区。土壤有效氮、有效磷、有效钾含量(w,后同)分别为7.3～343.3、0～175.5、0～739.9 mg·kg-1,其中种植区显著高于背景区,种植区处于高量和过量范围的比例高达64%、91%和92%。土壤有效钙和有效镁含量分别为0.5～7 540.7 mg·kg-1和0.4～387.0 mg·kg~(-1),其中背景区土壤有效钙和有效镁含量处于缺乏和低量的果园比例合计高达84%和99%;种植区土壤有效钙和有效镁含量显著高于背景区,但有59%果园土壤有效钙含量不足。赣南脐橙园土壤有效铁、有效锰、有效锌和有效铜含量分别为0.2～305.7、0.4～135.3、0.01～20.07、0.01～82.41 mg·kg~(-1),其中种植区含量超出适宜范围的果园分别占78.0%、62.0%、69.0%和76.0%,显著高于背景区。【结论】与赣南脐橙园背景区相比,种植区土壤pH呈下降的趋势,而种植区土壤有机质以及氮磷钾等有效态养分元素含量均呈增加的趋势,且主要表现在0～20 cm土层显著增加。赣南脐橙园背景区和种植区土壤普遍存在酸化严重、有效钙和有效镁含量不足的问题,而种植区土壤有效态氮、磷、钾、铁、锰、锌和铜等养分普遍过量也值得关注。     

寿光耕层土壤养分及金属元素分析

对山东寿光南部4个乡镇19个自然村大棚耕层土壤养分及金属元素含量进行了调查,以期为大棚土壤科学施肥提供依据。结果表明:耕层土壤养分总体含量很丰富,土壤平均pH6.25,平均C/N为13.96,全氮平均含量为3.12g·kg~(-1),有机质含量很丰富,平均值为41.25g·kg~(-1),有效磷、速效钾含量很丰富,平均值分别为1 492.1、776.6mg·kg~(-1);土壤中金属元素有效钙、镁、铁、锌、铜、锰含量均极为丰富,平均值分别为6 007、1 053、178.29、91.77、11.35、221.8mg·kg~(-1)。因此,在实践中应当控制并减少施肥量,确保环境安全。     

新疆皮山县石榴果园土壤养分状况初步分析

为了解新疆石榴主产区土壤养分状况,采用室内分析测定,对石榴果园不同树龄的0~20cm、20~40cm范围内石榴园土壤有机质、全氮、速效氮、速效磷、速效钾含量进行了测定分析。结果表明:石榴园不同树龄、不同土层深度的土壤有机质含量范围分别为0.576 0~0.659 5g·kg~(-1)、0.402 5~0.504 0g·kg~(-1),平均值分别为0.617 8、0.453 3g·kg~(-1);土壤全氮含量变化范围分别为0.069 5~0.072 5mg·kg~(-1)、0.058 5~0.060 5mg·kg~(-1),平均值分别为0.071 0、0.059 5mg·kg~(-1);土壤速效氮含量变化范围分别为54.079 0~63.106 0mg·kg~(~(-1))、52.091 0~57.153 5mg·kg~(-1),平均值分别为58.592 5、54.622 3mg·kg~(-1);土壤速效磷含量变化范围为32.362 5~36.704 0mg·kg~(-1)、19.683 5~22.042 5mg·kg~(-1),平均值分别为34.533 3、20.863 0mg·kg~(-1);土壤速效钾含量变化范围为309.088 0~395.853 2mg·kg~(-1)、301.294 2~365.353 0mg·kg~(-1),平均值分别为352.470 6、333.323 6mg·kg~(-1)。分析发现,石榴果园土壤中除速效钾含量偏高外,有机质、全氮、速效氮含量偏低,速效磷含量中等,石榴园土壤养分不平衡。该试验为今后石榴园土壤合理施肥提供科学依据。     

伸根空间对植物卷材养分含量的影响

伸根空间是植被生态系统植物所需养分的直接提供者。以经植被恢复3年后的坡面等的植物卷材伸根空间基质为对象,分析伸根空间对基质养分含量的影响。结果表明:养分含量均值全氮(N)12.350g·kg~(-1),全磷(P)5.519g·kg~(-1),全钾(K)6.329g·kg~(-1),全钙(Ca)16.195g·kg~(-1),全镁(Mg)7.192g·kg~(-1),全铁(Fe)18.245g·kg~(-1),全锰(Mn)0.250g·kg~(-1),有效铜(Cu)1.927mg·kg~(-1),有效锌(Zn)6.675mg·kg~(-1);显著性分析表明,伸根空间对养分元素含量均具有显著性影响,有正显著影响也有负显著影响;以水泥盒(D)为对照,部分养分元素损耗速率加快,如全N、全Mn、有效Cu等,也能降低部分元素的损失速率,如全K、全Ca、全Mg、全Fe、有效Zn等。此外,对于全P,1∶0.5坡面(P2)、沙场(S)能加速P元素的损失,而其余伸根空间能够降低损失速率。根据全国第2次土壤普查养分分级标准,所有伸根空间基质K元素均表现为缺-极缺,且有效Cu在屋面(W)和渣场(Z)表现为中等,其余测定的养分元素含量均表现为稍丰/丰,证明植物卷材对于伸根空间养分保持具有积极意义。     

奉节脐橙园土壤养分状况普查及其与叶片养分和产量相关性研究

【目的】探索奉节脐橙园土壤和叶片营养状况及它们对果实产量的影响,以期为合理施肥和高产管理提供理论依据。【方法】对奉节脐橙产区148个果园土壤样品和柑橘叶片进行采样,同时调查了果实产量,分析了土壤、叶片营养状况,进行了叶片营养与果实产量的相关性分析。【结果】奉节脐橙产区土壤pH变幅较大,平均值为7.12,多数为碱性,土壤有机质含量(w,后同)较为丰富,超过15 g·kg~(-1)的比例为85.81%。总体上,奉节脐橙园土壤碱解氮缺乏很严重,平均含量仅为78.71 mg·kg~(-1),而有效P、速效K含量较为丰富,平均值分别为37.02 mg·kg~(-1)和191.67 mg·kg~(-1)。交换Ca含量极为丰富,适宜值以下的比例为0,而Mg极度缺乏,其含量100%处于缺乏范围。微量元素中有效Fe、Mn、Zn、Cu较为丰富,其含量平均值分别为40.72 mg·kg~(-1)、24.04 mg·kg~(-1)、2.69 mg·kg~(-1)和2.17 mg·kg~(-1)。有效B较为缺乏,平均值为0.67 mg·kg~(-1)。奉节脐橙叶片营养元素N、P、K、Ca、Fe、Mn和Cu较为丰富,其含量平均值为29.45 g·kg~(-1)、1.50 g·kg~(-1)、13.32 g·kg~(-1)、41.23 g·kg~(-1)、133.17 mg·kg~(-1)、42.97 mg·kg~(-1)和9.51 mg·kg~(-1),而Mg和B较为缺乏,平均值分别为3.90 g·kg~(-1)和49.76 mg·kg~(-1),Zn元素极度缺乏,平均值为16.65 mg·kg~(-1)。叶片P、K、Zn含量与果实产量达到了显著或极显著相关,相关系数分别为-0.332、-0.205、-0.213。奉节脐橙产区不同乡镇土壤和叶片营养元素差异较大,通过叶片营养元素含量聚类分析10个乡镇可以分为5类。【结论】奉节脐橙园各乡镇营养差异较大,总体来讲,今后生产管理的重点是适度调节土壤pH,合理施用N、P、K肥,增施有机肥、Mg、Zn和B肥。     

地方柑橘良种（贡柑）新建果园土壤和树体养分分布特征

测定、分析广东省肇庆地区五和镇新建贡柑果园土壤养分、树体矿质元素含量及分布特征和相关性。结果表明：供试果园土壤pH值偏低,有机质含量中等偏低,土壤缺乏交换性钙、交换性镁和有效硼等元素。叶片中矿质元素含量与土壤养分之间有一定的相关性,春梢和秋梢叶片中不同矿质元素含量分布规律不同,并受土壤相关元素丰缺度、矿质元素在树体内的分配与再分配特性等因素的影响。     

广东省沙糖桔主产区果园土壤与树体养分状况分析

为了探讨沙糖桔叶片黄化与矿质养分的关系,对广东省沙糖桔主产区(肇庆市和云浮市)的53个果园进行土壤和叶片养分调查和分析.结果表明,沙糖桔果园土壤整体偏酸,有机质、土壤碱解氮、速效钾和有效锌含量基本上处于适宜水平,交换性镁和有效钙含量偏低,有效磷含量偏高;植株普遍缺氮、磷、镁和锌,缺乏程度以镁最严重;叶片中各养分间以及叶片养分与土壤pH值、有机质及其有效养分间存在着一定的相关性.缺镁是造成沙糖桔叶片黄化的主要原因.     

‘琯溪蜜柚’园土壤和树体的硫素营养研究

【目的】研究‘琯溪蜜柚’园土壤和树体的硫素状况及其影响因素,探讨土壤硫富集与土壤酸化以及钙、镁淋失的关系。【方法】采集和分析314个‘琯溪蜜柚’园土壤、叶片样品以及27个土壤剖面样品的硫含量。【结果】‘琯溪蜜柚’园土壤有效硫含量(w,后同)范围10.98～116.65 mg·kg~(-1),平均值55.63 mg·kg~(-1),土壤有效硫高量(30 mg·kg~(-1))、适量(16～30 mg·kg~(-1))和低量(16 mg·kg~(-1))的比例分别为83.44%、13.06%和3.50%,土壤有效硫含量随土壤有机质含量、阳离子交换量和黏粒(0.002 mm)含量的增加而提高,随种植年限的延长呈升高的趋势,剖面土壤有效硫含量平均值为40～60 cm20～40 cm0～20 cm。相关分析表明,土壤有效硫含量与土壤pH以及交换性钙、镁含量均呈极显著负相关‘。琯溪蜜柚’叶片硫含量的范围为0.24%～0.53%,平均值为0.34%,叶片硫适量(0.2%～0.4%)和高量(0.4%)的占比分别为86.94%和13.06%。【结论】‘琯溪蜜柚’园土壤和树体均存在硫过量问题,土壤硫富集会导致土壤酸化、促进钙和镁的淋失,生产上应减少含硫肥料的使用。     

棕壤土苹果园土壤与叶片营养关系初探

通过苹果园土壤、叶片养分相关性分析 ,烟台棕壤土果园土壤有机质、交换性镁、有效锰、有效锌、有效硼与苹果叶片养分含量呈正相关 ,其中有效锌、有效硼与叶片养分含量分别达到显著和极显著相关 ,相关方程分别为 y =2 0 .88+8.479x和 y=4.2 9+ 6 7.71x ;土壤有效磷、速效钾、交换性钙、有效铁与苹果叶片养分含量呈负相关。土壤交换性Ca/Mg以 3.7～ 6 .2较适宜 ,过大不仅影响树体对镁的吸收 ,并且也影响到对钙的均衡吸收 ,其中对镁吸收的影响达到显著水平 ;土壤Mg/K以大于 0 91以上较适宜 ,过低影响树体对钾的吸收 ,二者达到显著水平     

Upstream-to-downstream changes in nutrient export risk

Nutrient export coefficients are estimates of the mass of nitrogen (N) or phosphorus (P) normalized by area and time (e.g., kg/ha/yr). They have been estimated most often for watersheds ranging in size from 10² to 10⁴ hectares, and have been recommended as measurements to inform management decisions. At this scale, watersheds are often nested upstream and downstream components of larger drainage basins, suggesting nutrient export coefficients will change from one subwatershed to the next. Nutrient export can be modeled as risk where lack of monitoring data prevents empirical estimation. We modeled N and P export risk for subwatersheds of larger drainage basins, and examined spatial changes in risk from upstream to downstream watersheds. Spatial (subwatershed) changes in N and P risk were a function of in-stream decay, subwatershed land-cover composition, and subwatershed streamlength. Risk tended to increase in a downstream direction under low rates of in-stream decay, whereas high rates of in-stream decay often reduced risk to zero (0) toward downstream subwatersheds. On average, increases in the modeled rate of in-stream decay reduced risk by 0.44 for N and 0.39 for P. Interactions between in-stream decay, land-cover composition and streamlength produced dramatic changes in risk across subwatersheds in some cases. Comparison of the null cases of no in-stream decay and homogeneously forested subwatersheds with extant conditions indicated that complete forest cover produced greater reductions in nutrient export risk than a high in-stream decay rate, especially for P. High rates of in-stream decay and complete forest cover produced approximately equivalent reductions in N export risk for downstream subwatersheds. This revised version was published online in August 2006 with corrections to the Cover Date.     

Effects of time and rate of nutrient application on foliar nutrient concentration and cold hardiness in Viburnum species

Viburnum plicatum Thunb. f. tomentosum Rehd. and Viburnum dentatum L. were fertilized with N, P, and K at a high or low rate during late spring and late summer. V. plicatum f. tomentosum absorbed more K than N and P. Potassium applications to soil increased foliar K significantly, but increases were much greater following spring applications than following late summer applications. There was no luxury consumption of K by V. dentatum. N and K applications decreased cold hardiness of V. plicatum f. tomentosum in late October. Nutrient applications had no effect on cold hardiness of V. dentatum regardless of date of application.     

Crop production in recirculating nutrient solution

The development of a low capital cost technique for crop production in recirculating nutrient solution is described with special reference to greenhouse tomato production. Tomato trials in heated glasshouses are reported and attention is drawn to the decline in root growth which began in late April and ceased in early June. It is suggested that this “May check” may be related to time of year and not to plant age.     

Production and quality of greenhouse roses in recirculating nutrient systems

Greenhouse-grown rose plants were grown in either a non-recirculating (open) nutrient system, or a recirculating (closed) nutrient system with or without one of five amendments. Recirculation had no effect on harvest parameters during the first 8 weeks of the harvest period, but had a negative impact on stem length during the second 8 weeks, and on stem number and length when averaged over the entire harvest duration. Differences were not likely caused by changes in electrical conductivity or macro-nutrient concentrations of the nutrient solutions. Amendments to the recirculated solutions consisted of increased concentrations of Ca, B or Si, reduced pH, or use of an adsorbent resin to remove specific organic molecules. All amendments mitigated the negative effects of recirculation on at least two harvest parameters, but only during the second-half of the harvest period. With the exception of the intentional changes, mineral status of the nutrient solutions were similar in all recirculated treatments. Leaf chlorosis was observed in all recirculation treatments. It is likely that the reduction in rose quantity and quality in recirculation is caused by a combination of factors, some of which were ameliorated through the addition of specific amendments to the solution.     

A comparison between two methods to control nutrient delivery to greenhouse melons grown in recirculating nutrient solution culture

Two methods to control nutrient delivery to greenhouse melon plants grown with the nutrient film technique were compared: a conventional control system based on the adjustment of electrical conductivity (EC) of the recirculating nutrient solution, and a programmed nutrient addition, which was based simply on pre-established weekly supply of N, P and K without any attempt to maintain constant values of nutrient concentration and EC. The method to control nutrient supply did not influence significantly fruit yield or quality, but the nutrient addition reduced the crop consumption of water, N, P and K by 40–60% with respect to the EC method.     

设施菜地土壤基础养分含量分析

为了给设施蔬菜减量施肥提供依据,结合设施蔬菜种植户施肥调研结果,以及室内土壤样品测定结果,研究了新乡市牧野区设施蔬菜地土壤基础养分含量和施肥中存在的主要问题。结果表明,该区土壤质地良好,磷钾丰富,氮含量中等,有机质缺乏,pH值约为6.5,为非盐渍化土壤。除类金属总砷含量有部分地块超标外,土壤中其余金属元素含量均未超标。选择优质商品有机肥和微生物菌肥做为底肥的种植户只占到10%,而选择生粪的占65%以上。每茬作物化肥施用量可达250 kg·667 m-2。因此,建议该地区设施蔬菜种植施用优质商品有机肥1 200 kg·667 m-2,并逐渐降低化学肥料追肥次数和数量,不断增加生物菌肥和有机水溶肥的施用。     

The nutrient levels in fruiting and non-fruiting terminals of three mango cultivars

The leaf nutrient status of 3 mango cultivars, determined in fruiting and non-fruiting terminals after fruit harvest (June 1976) from 20 orchards, were compared. N, P and Ca contents were significantly higher in ‘Dashehari’ than in ‘Chausa’ and ‘Lucknow Safeda’. The reverse was true for K, S and Zn contents. Mg and Mn contents were more or less at par in all the 3 cultivars. Leaves collected from non-fruiting terminals contained significantly higher amounts of N and P in all the 3 cultivars, but K, Ca, S and Zn only in 2 cultivars, as compared to those from fruiting terminals. Mn and Fe contents in both kinds of terminals were more or less at par in all the 3 cultivars.     

Spatial variation in forage nutrient concentrations and the distribution of Serengeti grazing ungulates

Resident grazing ungulates in the Serengeti National Park, Tanzania, are conspicuously patchy in their distribution among regions of the Park. Linear programming models that maximize nitrogen (N) consumption by foraging ungulates in Serengeti regions having high and low resident animal densities were compared using forage ingestion rate and twelve nutritional requirements as simultaneously imposed constraints on forage choice. Model results indicate that (1) growing season N or crude protein is not limiting in either region although greater N ingestion is possible within the eastern corridor under other nutritional constraints, (2) grazing ungulates in the eastern corridor region occur in greater density and are capable of balancing dietary requirements solely from forage while simultaneously consuming more protein than ungulates in the northeast region, and (3) rarer landscape elements are most capable of providing ungulate dietary requirements in both the northeast and eastern corridor. These results provide a nutritional basis to understand patchy spatial distributions of grazers within Serengeti regions and landscapes, and provide a partial test of the hypothesis that large generalist herbivores should graze rare forages more frequently. The ability of uncommon landscape elements to support ungulate grazing over the growing season is supported by previous ecosystem studies that demonstrate the capability of grass forages for compensatory growth and the ability of grazing to stimulate rapid nutrient recycling.