重庆渝东北植烟区土壤交换性钙镁与土壤属性的关联特性研究

为明确重庆渝东北植烟区土壤中交换性钙、镁养分状况与土壤属性的关联特性，为烟区养分管理提供参考依据，利用GPS定位技术在渝东北植烟区采集了1 092个代表性土壤样品，对巫溪、巫山、奉节、万州、涪陵和丰都6个区县植烟土壤交换性钙和交换性镁含量分析，同时与其他土壤属性进行关联分析。结果表明：重庆渝东北植烟土壤交换性钙、镁含量丰富，其平均值分别为10.85 cmol/kg和1.79 cmol/kg，但也存在缺乏现象，且区域分布不均衡。总体来看，土壤交换性钙缺乏(<6 cmol/kg)占比28.30%，土壤交换性镁缺乏(<1.0 cmol/kg)占比42.75%。涪陵县与丰都县的土壤交换性钙、镁缺乏最严重，占比分别为40.00%和55.00%。丰都县与万州区土壤交换性钙、镁含量最适宜烤烟种植，占比分别为42.00%和36.61%。母质是影响土壤交换性钙、镁含量的重要因素，二叠系泥灰岩发育形成的土壤交换性钙、镁含量较高，侏罗纪紫色砂岩含量最低。植烟土壤pH、阳离子交换量与交换性钙、镁存在显著正相关关系，而土壤交换性酸总量与二者呈显著负相关，交换性钙镁缺乏是引起烟田酸化的主要原因。1～2...     

菜心的土壤钙、镁营养诊断指标及施肥效应研究

在不同地方,不同钙、镁含量水平的菜园土壤进行菜心钙、镁肥田间试验。根据20个试验点的钙肥试验和15个试验点的镁肥试验结果,分别建立菜心相对产量与土壤交换性钙、镁含量的回归方程。研究结果表明:菜心产量与土壤交换性钙、镁含量分别呈抛物线相关;在质地为中壤土的菜田上种植菜心,土壤交换性钙的适宜含量为4.26￣9.60cmolL-1,交换性镁的适宜含量为2.01￣2.31cmolL-1;在参试的所有菜田中,施钙肥增产显著的菜田占50%,增产率为0.65￣33.8%;施镁肥增产显著的菜田占47%,增产率为-1.6%￣34.7%。     

长期施肥与地膜覆盖对棕壤交换性钙、镁的影响

本文以沈阳农业大学棕壤长期定位试验站（始于1987年）玉米连作试验为研究对象,探讨了施肥与地膜覆盖对棕壤中交换性钙、镁含量的影响,以及交换性钙、镁和pH之间的相关性。研究结果表明:试验地040 cm土壤交换性钙含量在1.34～2.52 g/kg之间,交换性镁含量在0.30～0.66 g/kg之间,目前都比较丰富,作物基本不会出现缺钙缺镁症状。经过24年的不同施肥处理,施有机肥土壤表层（020 cm）交换性钙和交换性镁含量呈明显增加趋势,施用化肥土壤表层交换性钙和交换性镁含量呈明显下降趋势。无论不覆膜还是覆膜,单施化肥底层（2040 cm）土壤交换性钙和交换性镁含量大于表层;施用有机肥土壤交换性钙含量在两个层次差异不明显,交换性镁含量土壤表层大于底层。覆膜与不覆膜相比,单施化肥土壤覆膜后表层土壤交换性钙和交换性镁含量增加,底层含量降低,而有机肥处理表现的不明显。土壤表层交换性钙和交换性镁与pH之间都有极显著的正相关关系。     

丹江口柑橘园土壤和叶片营养状况调查分析

在丹江口柑橘主产区42个柑橘园采集了土壤和叶片样品并进行养分测定,旨在研究土壤和叶片营养元素状况及相关性。结果表明,1)97.6%的柑橘园土壤pH值适宜柑橘生长;土壤有机质、碱解氮、有效磷、速效钾、有效硼、交换性镁、有效铁、有效铜、有效锌、交换性钙和有效锰处于缺乏或低量水平的柑橘园分别占71.4%、95.2%、64.3%、45.2%、100.0%、11.9%、16.7%、26.2%、14.3%、0.0%和0.0%。2)叶片氮、磷、钾、钙、镁、铜、锌、硼、铁和锰含量缺乏的柑橘园分别占31.0%、71.4%、81.0%、38.1%、83.3%、97.6%、95.2%、40.5%、0.0%和0.0%。3)土壤交换性钙、交换性镁、有效铁、有效锰和有效硼的丰缺状况与叶片中对应元素显著正相关,其它土壤营养元素与叶片相应元素无显著相关性。因此,建议柑橘园在营养管理上应因地制宜,增施有机肥及硼肥,合理施用氮、磷和钾肥。     

夷陵区柑橘园土壤和叶片养分状况研究

为研究夷陵区柑橘园土壤和叶片营养元素状况及相关性，在柑橘主产区采集了 41个土壤和叶片样品进行养分测定分析。结果表明，1)柑橘园土壤 pH均值 5.5，偏酸性柑橘园占 22%。有机质、碱解氮、速效钾和有效硼处于低量缺乏的比例分别为 33.1%、68.3%、36.6%和 100%，其他土壤养分含量均适宜偏高水平。2)叶片中氮、钾、钙、镁和锌含量缺乏的柑橘园分别占34.1%、87.8%、36.6%、65.9%和95.1%。叶片磷、铁、锰、铜和硼含量在适宜偏高水平。3)土壤碱解氮、交换性钙、交换性镁、有效铁和有效硼的含量与叶片中对应元素存在显著正相关；土壤有效钾和有效铜与叶片对应元素显著负相关；土壤交换性钙与土壤 pH极显著正相关；土壤有机质与土壤碱解氮、交换性镁以及叶片镁极显著正相关。因此建议夷陵区柑橘园应有机无机肥配施，增施硼、锌和镁肥，同时可施用适量石灰改良酸性土壤。     

铜仁市植烟土壤交换性钙镁空间分布特征及其影响因素分析

为明确贵州省铜仁市植烟土壤中交换性钙和镁的状况,以铜仁2019年植烟耕层土壤交换性钙镁为研究对象,利用多元统计学和地统计学方法分析了土壤交换性钙镁空间变异特征及其影响因素。结果表明,铜仁植烟土壤交换性钙、镁含量整体丰富,平均值分别为1.72、0.27 g·kg^-1,但仍有19.31%的交换性钙和27.59%地区的交换性镁含量处于低与极低水平。植烟土壤中钙镁比处于适宜范围的比例仅占29.70%,说明钙镁比失调较严重。土壤交换性镁含量总体呈现由西北向东南逐渐增加的趋势,土壤钙镁比总体呈现由中部向东南和西北逐渐减小的趋势,思南中部钙镁比处于最高值,江口南部与松桃南部钙镁比处于最低值。植烟土壤交换性钙、镁含量及其比值的空间变异是由结构性因素和随机性因素共同作用的结果。pH对交换性钙、镁空间变异的影响最大,分别能够独立解释其变量的41.6%、55.7%,且与交换性钙、镁分别呈现幂函数和三次函数关系,随着pH值升高,土壤中交换性钙和镁含量升高。综上,贵州铜仁植烟土壤空间分布不均匀、差异性较大,钙镁比失调比较严重,pH值对交换性钙、镁空间变异的影响最大,并与其呈极显著正相关。因此,铜仁烟区在指导钙镁施肥时要注意其空间差异性、做到分类指导,可以通过调控钙镁肥料施用量或含钙镁的改良剂调节土壤pH值来达到平衡土壤养分的目的。本研究可为铜仁市烟田钙镁养分管理提供科学依据。     

2株真菌对土壤营养元素动态变化的影响

采用真菌室内土培的方法,进行了2株真菌(草酸青霉菌和黑曲霉菌)对土壤pH值、有效磷、交换性钙、镁及有效性铁、锰、铜、锌的动态变化的研究。结果表明,添加草酸青霉菌和黑曲霉菌后,土壤的pH值显著降低,有效磷、交换性钙、镁和有效性铁、铜、锌含量显著增加,有效锰含量显著降低。当土壤中加入微生物所需大量营养元素后,微生物生长代谢能力增强,增加了土壤营养元素有效态含量。总体上,草酸青霉菌增加土壤营养元素有效性的能力高于黑曲霉菌。添加草酸青霉菌处理与对照相比,第21d时土壤有效磷含量增加35.89%,第12d时交换性镁、有效锌分别增加20.02%和37.4%,第15d时有效铁增加43.0%,在第18d时交换性钙、有效铜分别增加14.51%和46.9%,而第21d时,有效锰含量降低32.8%。     

云南丽江植烟土壤中微量营养元素状况及施肥对策

在云南丽江烟区采集273个土壤样品和烟叶样品进行分析化验。结果表明,丽江市植烟土壤中微量营养元素含量存在较大的差异,土壤平均交换性钙含量为3338.82 mg kg-1,交换性镁342.26 mg kg-1,有效锌2.21 mg kg-1,有效硼0.54 mg kg-1,有效钼0.44 mg kg-1,水溶性氯38.37 mg kg-1。植烟土壤交换性钙、交换性镁和有效钼含量整体比较充足,有效锌含量整体适宜,有效硼含量普遍缺乏;尽管土壤中水溶性氯含量较高,但烟叶中氯含量较低。为此生产上提出了"控镁和补硼"的施肥措施,对于连年干旱且水溶性氯含量高的植烟土壤要严禁施用含氯肥料。     

井冈蜜柚果园土壤和叶片养分状况及果实品质研究

为研究吉安市井冈蜜柚果园土壤和叶片营养元素状况及果实品质,在井冈蜜柚主产区采集了33个代表性果园的土壤、叶片及果实样品进行测定分析。结果表明:1)井冈蜜柚果园土壤 pH 均值 4.82,酸性至强酸性井冈蜜柚果园占 90.91%。土壤碱解氮、有效磷、交换性钙及交换性镁含量处于缺乏的井冈蜜柚果园分别占24.24%、30.30%、100%及90.91%;土壤有机质和速效钾含量均处于中等偏上水平。2)叶片中氮、钾、钙和镁含量缺乏的井冈蜜柚果园分别占 15.16%、12.13%、100%和60.61%;叶片磷含量在适宜偏高水平。3)井冈蜜柚果实品质:单果重均值886.12 g,果形指数均值1.05,维生素C含量均值0.71 mg/g,可溶性固形物均值10.82%,可滴定酸均值0.78%,固酸比均值15.57,且桃溪蜜柚品质较佳。4)土壤碱解氮、交换性镁的含量与叶片中对应元素存在显著正相关关系;叶片钙、镁含量存在极显著的正相关关系;土壤pH与叶片钙、镁含量存在显著正相关关系;叶片钙含量、镁含量与果实单果重存在极显著正相关关系。因此,吉安市井冈蜜柚果园应加强钙、镁等元素的补充以促进果实品质的提升及产量的提高,同时可施用适量石灰改良酸性土壤,提高土壤养分的有效性。     

土壤-烤烟矿质营养元素相互关系的主组分分析

对云南五种植烟土壤上烤烟三个品种、六个生育期烟叶中钾、磷、硫、钙、镁、铁、锰、锌、铜、硼浓度和烟株根区土壤中ＡＢ／Ｄ联合提取的养分含量及土壤ｐＨ、有机质和碱解氮的测试数据，用主组分分析（ＰＣＡ）方法，讨论土壤─烤烟系统矿质营养元素的相互关系及交互作用。结果显示：①烟叶矿质营养元素浓度随烤烟生育期有规律的变化，受根区土壤化学性质影响的变异大于品种间的差异；②烟叶钾、磷、铜、硼表现明显的稀释效应，钙、镁表现积累效应；③烤烟钾、磷、铜、硼营养存在相互协同作用，钙对钾、磷、铜、硼营养有明显的拮抗作用。④增加土壤有机质，利用钾、磷、铜、硼的协同作用，减轻钙对钾、磷、硼的拮抗是改善烤烟营养，提高烤烟产量品质的关键之一。     

Soil solarization enhances growth and yield in dry beans

Abstract

Dry beans are one of the most important crops in Mexico. However, in the last decade this crop averaged yields as low as 0.7 tons per hectare. Therefore, the purpose of this study was to test if soil solarization is a suitable pre-planting soil treatment to improve growth, nutrition and yield of beans in northeast Mexico. Five different periods of soil solarization were evaluated during the spring of 2008: 0, 30, 40, 50 and 60 days of soil solarization. Soil temperatures were recorded during soil solarization to estimate total heat units. After soil solarization bean seeds were sown in plastic-mulched rows and leaf area, potassium, calcium and magnesium concentration and yield were measured. Leaf area and concentrations of potassium, calcium and magnesium were increased by all treatments of soil solarization when compared with the non-solarized soil. Sixty days of soil solarization produced yields of 3.7 tons per hectare while no solarization produced yields of 2.1 tons per hectare. Soil heat units were positively correlated with yield, suggesting that the increase in yield is due to an increase in heat accumulation during soil solarization in addition to an increase of leaf area and to an enhancement of plant nutrition.     

Macro element status of Mandarin orchards in Southern Turkey

Abstract

Citrus nutrition and fertility of the orchards are not intensively studied in Turkey compared to the size of orchards and amount of production. A survey study was conducted in Eastern Mediterranean Coast of Turkey to evaluate the macro element status of Mandarin orchards and to define potential correlations between the soil parameters and leaf element contents. Twenty five mandarin orchards were selected for the survey study. Soil and leaf samples were collected from each orchard based on the size and uniformity. The amounts of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) were measured in soil and leaf samples. The results indicated that there were not apparent nutrient deficiencies in the soils, however, the macro element deficiencies in the leaves were detected. Only a few number of correlations existed between the soil and leaf parameters. Previous fertilizer applications by growers should be considered in the current fertilizer programs.     

Diagnostic Leaf Nutrient Norms and Identification of Yield-Limiting Nutrients of Mango in Eastern Plateau and Hill Region of India

The leaf nutritional status of mango orchards was assessed using diagnosis and recommendation integrated system (DRIS). The DRIS norms, which showed higher variance and lower coefficients of variation, are found to have greater diagnostic precision. As per DRIS indices, a relative deficiency for magnesium, zinc, and boron corresponding to relative sufficiency for calcium, nitrogen, phosphorus, sulfur, and potassium was detected in 9-year-old mango orchards. For the younger orchards (6–7 year old), the order of requirement of nutrients was found to be calcium > sulfur > potassium > boron > nitrogen > phosphorus > magnesium > zinc. Boron was found as the most yield-limiting elements in all age group of plants. When the DRIS indices were compared on the basis of soil pH, calcium and magnesium were most yield-limiting nutrients below pH 5.5, while nitrogen, zinc, and boron were found to be most limiting above pH 5.5.     

施镁对缺镁葡萄叶片和果实矿质元素含量的影响

在大田条件下,对缺镁的葡萄园进行了土施和叶面喷施硫酸镁肥的试验,探讨缺镁条件下,施镁对葡萄叶片和果实矿质营养吸收的影响,为葡萄施肥提供理论依据。采用裂区试验,主区设4个土施硫酸镁梯度,分别为0、112.5、150、187.5 kg/hm2,副区设3个叶面喷施硫酸镁浓度,分别是0%、0.2%、0.4%。结果表明:土施和叶面喷施硫酸镁在增加缺镁葡萄镁含量的同时,促进了钾、钙和锰的吸收,但降低了叶片和果实中锌含量,对铁和铜的影响不显著。土施镁肥极显著增加了叶片和果实中镁含量,叶面喷施极显著增加了叶片镁含量,但对果实镁含量影响不显著;土施150 kg/hm2同时叶面喷施0.4%硫酸镁肥,可提高叶片和果实中镁及其它矿质元素的含量。     

Seasonal Changes in Macronutrients in the Leaves and Fruit of Kiwiberry: Nitrogen Level and Cultivar Effects

ABSTRACT

Nutrient use efficiency and overall plant fertilization strategies are key issues in food production in increasingly adverse environmental conditions. The plant Actinidia arguta (Siebold et Zucc.) Planch. ex Miq. is a species that has increased cultivation in recent years. The aim of this study was to assess seasonal leaf macronutrient changes and the relationship between soil nitrogen (N) fertility and N, as well as the concentration of other leaf essential macronutrients. The experiment was conducted during the growing seasons of 2015–2016 and tested two cultivars: “Weiki” and “Geneva”. Soil N level had a significant impact on the concentration of all leaf macronutrients, except sulfur, in both cultivars. Leaf macronutrient concentration was significantly lower in 2015, which was characterized by a higher average temperature and lower precipitation than the long term averages. A clear downward trend for leaf N and potassium concentrations was observed during the vegetation period. In contrast, leaf calcium and magnesium concentrations increased gradually throughout the season, while phosphorus and sulfur concentration changes were more cultivar dependent. In the soil and climatic conditions in which study was conducted (Central Europe), a time from mid-July to mid-August seems to be the suitable for leaf sampling for diagnostic purposes. Fruit macronutrient composition was predominantly cultivar and year dependent.     

Impact of organic and inorganic nutrition on soil–plant nutrient balance in arecanut (Areca catechu L.) on a laterite soil

The study assessed the impact of continuous application of vermicompost and chemical fertilizers nitrogen, phosphorus and potassium (NPK) on arecanut in India. Key parameters examined were biomass production, nutrient uptake, yield, soil fertility and net benefit. Pooled analysis of 8-year data revealed that nutrient application registered significantly higher yield (2585–3331 kg ha^?1) than no nutrition (1827 kg ha^?1). Yields in organic nutrition were around 85% of the yields obtained in inorganic NPK. The concentrations of leaf N and K were significantly higher with NPK than with vermicompost. Vermicompost significantly increased soil organic carbon and the availability of calcium (Ca), magnesium (Mg), manganese (Mn) and copper (Cu), but reduced exchangeable K in soil. The total uptake of K and Ca together contributed positively to 75% variability in total biomass production. Nutrient removal of iron (Fe), P, K and Cu positively influenced the yield with about 81% variability. Biomass partitioning and nutrient uptake pattern are important for fertilization program of arecanut.     

银杏氮素营养诊断技术研究

应用果园调查、土壤植株化验分析与大田氮肥施用量试验相结合的方法 ,对银杏氮素营养诊断技术进行了研究。结果表明 ,土壤氮素的最佳诊断形态为土壤有效氮 ,其诊断指标 (mg/kg)为 :高 115.2 ,中 78.8～ 115.2 ;低78.8。银杏植株氮素营养诊断最佳诊断时期为 7月 ,最佳诊断部位为长枝条 8位叶 ,诊断形态为全氮 ,其诊断指标 (N % )为 :高 2.04、中 1.80～ 2.04、低 1.80。     

Dynamics and Nutrient Release Pattern of Silica Sources in a Typical Entisol of Tropical Humid Region of Kerala

Silicon is considered as a beneficial element for crop nutrition especially for monocots. In order to study the effect of addition of different silica sources on the nutrient release pattern from an Entisol, a laboratory incubation study was conducted with three silica sources viz., sodium silicate, calcium silicate, and potassium silicate each @ 200 ppm and 400 ppm per kilo gram soil. The positive effect of addition of silicates was obvious on soil reaction, available Si, P, K, Ca, and Mg. Release of plant available silicon was the highest at 60th day after incubation (DAI) with potassium silicate @ 400 ppm per kg soil. Sodium silicate @ 200 ppm resulted in the highest exchangeable magnesium concentration at 45th DAI. The result of the study implies the positive influence of silicates on soil acidity as well as on enhancing the availability of phosphorus, potassium, calcium, and magnesium in an Entisol.     

Response of Forage Chicory Seedlings to Available Soil Phosphorus in Two Soils in a Controlled Environment

Poor phosphorus (P) fertility is a problem limiting productivity on unimproved Appalachian soils and has been implicated in poor palatability of forage chicory (Cichorium intybus L.). Three cultivars were grown in a greenhouse at varying soil P levels in Gilpin and Hagerstown silt loam soils and harvested 48 and 77 days after planting. In Gilpin soil, available soil P (ASP) was positively associated with dry shoot mass, leaf mass, leaf area, and leaves per plant and negatively associated with specific leaf area. In Hagerstown soil, ASP was positively associated only with only dry shoot and leaf mass. At equivalent ASP levels, dry shoot and leaf mass, leaf area, and shoot concentrations of P, potassium, calcium, and magnesium were always greater in Hagerstown than Gilpin soil, whereas specific leaf area was less. Equalization of ASP concentration and environmental conditions did not eliminate growth-limiting differences between Gilpin and Hagerstown soils for chicory.