荔枝叶片养分含量动态及不同比例钾、氮肥施用效应

【目的】探索荔枝叶片养分含量的周年变化规律及钾、氮肥不同施用比例对荔枝产量及其种植效益的影响,为荔枝生产中的施肥管理、营养调控与增产增效提供理论依据和实践指导。【方法】在大田栽培条件下,以1995年嫁接苗种植的国内主栽品种妃子笑为试材,设置钾、氮肥不同施用比例（K2O/N分别为0.6、0.8、1.0、1.2和1.4）5个处理,随机区组排列,于2009~2012年3个生长季在广东省惠州市荔枝主产区进行试验。在荔枝不同生育期定期采集荔枝叶片测定矿质元素含量,荔枝成熟时于田间按小区实收称重测产。【结果】荔枝叶片不同生育期的养分含量存在明显差异;在整个生育期,叶片养分含量的大小均表现为N﹥K﹥Ca﹥Mg﹥P﹥S﹥B﹥Zn﹥Mo;叶片K与Ca、Mg含量有极显著的负相关关系,K与Zn含量呈显著负相关,而Ca、Mg、Zn含量两两间呈显著正相关;叶片N与S、B含量呈显著负相关,而S与B呈极显著正相关;叶片P与Ca、Si含量呈显著负相关,而Ca与Si呈显著正相关。等氮基础上随着K2O/N比的提高,荔枝产量和种植效益均出现先升高后降低的规律;以K2O/N比例为1.0~1.2时荔枝产量最高、效益最好。【结论】在我国荔枝主产区以保持钾、氮肥养分施用比例（K2O∶N）为1.0~1.2为宜。     

广西壮族自治区与福建省荔枝园土壤养分肥力现状研究

掌握土壤养分肥力,是制定施肥策略的基础。本研究采集了广西壮族自治区荔枝主产区果园土壤样本185个,福建省荔枝主产区果园土壤样本25个,分析了土壤有机质和N、P、K、Ca、Mg、S、Cu、Zn、B、Mo含量,评价荔枝果园土壤养分肥力现状。结果显示:广西和福建两省荔枝果园土壤有机质、碱解氮、速效钾、有效钙、有效镁、有效硼、有效钼含量均为低水平,广西荔枝果园有效磷和有效锌为中下,福建为中上,有效铜中等,有效硫含量较高。整体上两省荔枝园土壤养分肥力较低且不平衡。不同荔枝主产区土壤养分肥力状况差别很大,硼是广西荔枝园土壤最普遍缺乏的元素,镁、钼次之。而镁是福建荔枝园土壤最普遍缺乏的元素,硼、钙次之。     

硼钼对大蒜产量及吸收利用氮磷钾的影响

采用田间试验,研究单施硼、钼和硼+钼配施对大蒜产量及氮磷钾吸收的影响。结果表明,硼、钼及其配合施用(B、Mo、B+Mo)比CK均增加大蒜蒜薹和蒜头产量,B+Mo最佳,蒜薹和蒜头产量分别为21 615.75和12 184.20 kg·hm-2,比CK处理分别显著增加14.66%和26.64%,硼比对照分别增产蒜薹与蒜头6.83%与21.75%,钼比对照分别增产蒜薹与蒜头8.92%与22.02%;硼、钼及其配合施用均提高大蒜全株及各部分氮磷钾吸收量,B+Mo处理大蒜全株N、P2O5、K2O吸收量分别为223.65、42.15、134.55 kg·hm-2,比CK分别显著增加17.03%、12.40%、10.74%。硼、钼及其配合施用使蒜头氮、磷、钾分配率比CK增加,硼、钼及其配合施用提高了大蒜氮磷钾肥(N、P2O5、K2O)养分效力系数,B+Mo的大蒜氮磷钾肥(N、P2O5、K2O)养分效力系数比CK分别增加17.88%、11.51%、10.95%。加权平均计算得到,每生产蒜薹1 000 kg+蒜头550 kg,及相应篙秆吸收带走N 10.39kg、P2O5 1.98 kg、K2O 6.42 kg,N∶P2O5∶K2O的比例为1∶0.19∶0.62,大蒜施肥的原则是适氮、控磷、慎钾,配合硼、钼肥。     

菜心平衡施肥技术研究

在土壤缺钼和硼、其它养分为中上至丰富水平条件下进行连续两茬菜心不同养分配施试验.结果表明,不施氮菜心产量与种植效益极显著下降,不施磷也有一定下降;不施钾则增产增收.施有机肥、喷钼和喷硼提高第一茬菜心产量和种植效益,第二茬则稍有下降,菜心Vc、总糖和亚硝酸盐含量均下降.根据菜地土壤养分状况,平衡施用氮、磷、钾、钼、硼和有机肥,才能获得高产、高效、安全的蔬菜生产.     

贵州土壤养分含量的变化与施肥管理

为了解近年来化肥施用量倍增后 ,贵州农田土壤养分含量的变化 ,在 1985年土壤调查的基础上 ,1998年再次进行了土壤和肥料调查。调查结果表明 ,在目前有机肥与化肥相结合 ,养分供应以化肥为主的施肥结构下 ,水田土壤有机质和氮、磷含量有所增加 ,旱地土壤有机质和全氮含量下降 ,土壤磷素有积累。由于钾肥施用不足 ,水田、旱地土壤钾素含量都明显降低。土壤微量元素中 ,有效态硼、锌、钼普遍增加。今后需增加钾肥的施用 ,并重视施用有机肥、秸杆还田和防治水土流失 ,以培肥土壤 ,实现农业的持续发展     

珠江三角洲几种主要蔬菜的镁硼钼适用量研究

为获得珠江三角洲地区蔬菜中微量元素的合理用量,通过在2地进行3种蔬菜施镁、硼、钼的田间试验,研究三种元素不同配比对三种蔬菜的影响。结果显示:(1)不同品种的蔬菜对中微量元素的需求量不同;相同品种蔬菜在不同地点土壤上的施镁、硼、钼肥效应不同;相同蔬菜镁、硼、钼配施比单独使用的施用量可大幅度减少,尤其是硼和钼可减少50%。(2)在施氮磷钾基础上单独施用镁、硼、钼,菜心的Mg适施量约为13.350～15.750 kghm-2;B的适施量约为0.990～1.065 kghm-2;Mo的适施量为0.375～0.420 kg hm-2。蒜青的Mg适施量约为1.500 kg hm-2;B的适施量约为0.450 kg hm-2;Mo的适施量为0.240 kg hm-2。苦瓜的施硼适用量范围在1.050 kg hm-2左右。(3)在施氮磷钾基础上镁、硼、钼配合施用,菜心的Mg适施量约为12.000 kghm-2、B适施量约为0.450 kghm-2、Mo适施量约为0.240 kghm-2;苦瓜的Mg适施量约为12.000～18.000 kghm-2、B适施量约为0.450～1.800 kg hm-2、Mo适施量为0.120～0.240 kg hm-2;蒜青的B和Mo适用量分别为0.900 kg hm-2和0.210 kg hm-2、镁的施用量则应<1.350 kg hm-2。(4)镁和硼的施用量不仅受试验地土壤交换性镁和有效硼含量水平的影响,还与土壤pH值和蔬菜目标产量有关。     

锰、硼对紫花苜蓿草产量和矿质元素含量的影响

采用叶面喷施的方法,研究不同水平锰、硼对紫花苜蓿草产量和矿质元素含量的影响。结果表明,喷施锰、硼可增加紫花苜蓿产草量;施锰200 mg/kg（Mn2处理）和硼600 mg/kg（B3处理）效果最好,草产量比CK分别显著提高809.49和1065.35 kg/hm2。喷施锰肥能显著提高紫花苜蓿锌和锰的含量,适量喷施能显著提高磷、钴、硒、铁和钼的含量;但喷施锰肥降低了紫花苜蓿钙、铜和硼的含量,适量喷施能显著降低钙和铜的含量。紫花苜蓿锰含量与施锰量呈正相关,硒、铜含量与施锰量呈负相关,而铁、锌含量随施锰量增加呈先升后降趋势。喷施硼肥显著提高了紫花苜蓿锌和磷含量,显著降低了钙、钼、硒的含量,而适量喷施硼肥能显著提高钴、铁、锰、硼的含量,但喷施硼肥未显著降低紫花苜蓿铜的含量。紫花苜蓿锌、硼含量与施硼量呈正相关,铁、钙、钼、铜、硒含量与施硼量呈负相关,而锰、磷含量随施硼量增加呈先升后降趋势。     

华南红壤中硼钼含量及硼钼肥对豆科作物的肥效

硼、钼是植物正常生长不可缺少的微量营养元素。作物种类和土壤类型不同,施用硼、钼肥料的效果也不一样。     

广东省柑桔园土壤养分肥力研究

掌握土壤养分肥力状况,是制定施肥策略的基础。本研究采集了广东省柑桔主产区果园土壤样本70个,分析了土壤有机质和N、P、K、Ca、Mg、S、Fe、Mn、B、Zn含量,评价土壤养分肥力现状并探讨其时空变化概况。结果显示:目前柑桔园土壤主要障碍因素是低镁缺硼及钾、钙、镁养分不平衡;与20世纪80年代末相比,土壤有效磷、锌、钾和氮含量有较大提高,有效钙含量降低,其余养分变化不大。土壤钙、镁含量在低水平上渐趋于相对平衡,而钾、镁不平衡状态仍然存在,甚至有所加剧;柑桔园土壤pH及多个中微量元素之间存在显著或极显著正相关关系。建议在柑桔果园增施镁、硼肥及石灰或其它碱性肥料,减施磷肥。     

施用硼、锌、钼肥对紫花苜蓿生长及品质的影响

试验阐明了在京郊土壤条件下施用硼、锌、钼肥对紫花苜蓿生长、品质和营养吸收的影响,为苜蓿的合理施肥提供了依据。结果表明:施用硼、锌和钼肥能够不同程度地提高苜蓿株丛数、改善结瘤、促进分枝、增加株高。微肥对产量的影响因土壤而异,当土壤有效锌、硼、钼含量分别低于1.8mg/kg、0.5mg/kg及0.1mg/kg时,施用微肥的增产效果明显。适当施用硼、锌、钼肥能够提高苜蓿粗蛋白质含量。苜蓿的吸氮量受硼、锌、钼肥影响显著,其中硼肥的作用最大,苜蓿的吸磷量受锌、钼的影响显著,吸钾量受硼、钼的影响显著。     

硒锌钼对黄土高原马铃薯和小白菜产量及营养元素与硒镉含量的影响

黄土高原旱地土壤微量元素硒锌钼潜在缺乏,不仅影响农作物产量,还降低农产品的矿物营养品质,研究施用硒锌钼肥料对该地区作物生长及可食部分营养元素含量的影响具有重要意义。通过田间试验,研究了硒锌钼肥单独土施、硒锌肥配施、硒锌钼肥配施对马铃薯和小白菜产量及营养元素和硒镉含量的影响。结果表明：硒肥提高了马铃薯块茎和小白菜叶片硒含量,分别由对照的0.02mg.kg-1和0.09mg.kg-1提高到1.51～2.15mg.kg-1和13.03～19.44mg.kg-1,钼肥提高了马铃薯块茎和小白菜叶片钼含量,分别由对照的0.43mg.kg-1和2.3mg.kg-1提高到1.03～1.16mg.kg-1和17.7～19.9mg.kg-1,单施与配施处理间无显著差异。锌肥土施或锌与硒、钼肥配合土施不但使小白菜叶片中的锌含量由对照的21.0mg.kg-1显著提高到48.1～68.4mg.kg-1,还使镉含量显著降低50%以上;施锌对马铃薯块茎的锌含量无显著影响。硒锌钼肥单施或配施均对马铃薯和小白菜产量及氮、磷、钾、硫、钙、镁、铁、锰、铜、硼含量无显著影响。因此,在黄土高原旱地,硒钼配合土施可同时提高马铃薯块茎的硒钼含量,硒锌钼配合土施可同时提高小白菜叶片的硒锌钼含量。     

硫素与其他营养元素的交互作用对作物养分吸收、产量和质量的影响

养分平衡是养分管理的必要环节,对增加作物产量和提高品质具有重要的作用.本文综述了硫(S)素与其他营养元素之间的交互作用对作物养分吸收、产量和质量的影响.S 与N或Ca、 K、Zn之间交互作用对养分吸收和利用是协同的,而S 与Mg、Mo、Cu、、Se、Fe、Sb、Cd、B、Br之间交互作用对养分吸收和利用是拮抗的.然而,S 与 P或Se之间的交互作用对养分吸收和利用是协同还是拮抗取决于作物种类、生长阶段和养分的浓度.N、S配施可以促进蛋白质的合成,提高作物产量和品质.由于S素与其他营养元素之间存在的这种拮抗作用,因此施用S肥可以减轻污染土壤重金属对蔬菜的毒害作用或加剧缺S土壤上蔬菜B和Mo的缺乏.     

Potassium fractions with other nutrients in crops: A review focusing on the tropics

Potassium (K), a plant nutrient with diverse roles to play in plant metabolism, is required in large amounts by most crops. It interacts with many other plant constituents to affect crop yield and quality. The magnitude of this interaction is high in areas of high cropping intensity, as in the tropics. The interaction of nutrients with K may be in the soil or in plant. Potassium modifies ammonium (NH₄ ⁺) ion fixation in soils to restrict nitrogen (N) availability. On the other hand, an antagonistic effect between K and NH₄ absorption has been suggested in which K absorption is restricted. Similarly, magnesium (Mg) or calcium (Ca) deficiency occurs from ion antagonism in acid soils following K fertilization and in soils with high exchangeable K. Sulfur (S) has been reported to increase K absorption and productivity of oilseed crops. With increasing levels of applied or soil K, the severity of phosphorus (P)‐induced zinc (Zn) deficiency in corn has been observed to decrease. Application of K decreases manganese (Mn) content and iron (Fe) toxicity in rice. Application of K has been reported to decrease B levels in plants and to increase incidence of boron (B) deficiency. Top‐dressing with K fertilizer was reported to lower the copper (Cu) content of alfalfa forage. In root, sugar‐producing, or fiber‐producing crops, the sodium (Na) and K relationship is important with the specific response to either element depending on which element is in low or high supply. Molybdenum (Mo) stimulated K uptake in alfalfa and com. In intensive agriculture with high‐yielding single crops or with multiple crops per year, farm management must include strategies to maintain substantial K reserves in the soil and to balance K nutrition with other fertilization practices.     

RELATIVE RESPONSE OF FORAGE AND SEED YIELD OF ALFALFA TO SULFUR,PHOSPHORUS, AND POTASSIUM FERTILIZATION

A field experiment was conducted from 2000 to 2007 on three-year old alfalfa stand near Star City in northeastern Saskatchewan to determine the influence of balanced application of sulfur (S), phosphorus (P), or potassium (K) fertilizers on forage dry matter yield (DMY) and seed yield, protein concentration (PC) in forage, concentration and uptake of total nitrogen (N), P, K, S, and boron (B) in forage and seed, and residual soil extractable P, exchangeable K and sulfate-S. Appropriate application of S, P, or K fertilizer nutrients was required to obtain optimum yield, PC, and nutrient concentration and uptake, especially when alfalfa was grown for hay production. Yield response to fertilization was much more frequent and much higher when alfalfa was managed as hay compared to when managed for seed production. The results suggest the importance of proper fertilization in increasing longevity of alfalfa stands. Under both hay and seed plots, there was only a small increase in residual sulfate-S from S fertilization, but significant accumulation of extractable P mainly in the 0–15 soil layer from P application. There was relatively higher concentration of exchangeable K in soil in the seed plots than in hay plots. In hay plots, concentrations of residual exchangeable K in soil were negatively related to DMY, especially in 2007. The findings suggest that when a soil is testing low (or deficient) in a nutrient and alfalfa growth is reduced, then alfalfa producers should consider applying fertilizers to supply adequate amounts of nutrients that are lacking in the soil, especially for optimum forage production. However, it is still difficult to predict accurately if a profitable alfalfa seed yield response to fertilization would occur, particularly when soils are testing marginal in some nutrient levels and yields are negatively affected by abnormal weather conditions (drought soil moisture conditions reducing plant growth, wet, cloudy and cool weather conditions decreasing pollination activity and late summer and/or early autumn frost damage to seed formation) that often occur in the growing season in this region.     

IMPROVING YIELD IN ALFALFA SEED STANDS WITH BALANCED FERTILIZATION

Field experiments were conducted from 2000 to 2007 on three-year or older alfalfa stands grown for seed production at various sites in northeastern Saskatchewan to determine the influence of balanced application of phosphorus (P), sulfur (S), or potassium (K) fertilizers on seed yield and longevity of alfalfa stands. Survey trials were also conducted to determine the possible reasons for low seed yields on some alfalfa seed fields by comparing “bad” (i.e., low alfalfa seed-yielding) and “good” (i.e., high alfalfa seed-yielding) areas within alfalfa seed stands. The results of alfalfa seed field survey trials suggest that poor seed yields in “bad” areas compared to “good” areas in most alfalfa stands were due to nutrient deficiencies and/or a soil fertility imbalance, as evidenced by soil tests for available nutrients. The findings of field research experiments indicated that application of P, K, or S fertilizer nutrients was essential to obtain optimum seed yield in most cases under normal soil moisture conditions. This also suggests the importance of balanced fertilization in increasing longevity of alfalfa seed stands over a number of years. In summary, the findings suggest that when a soil is testing low (or deficient) in a nutrient and alfalfa growth is reduced, then alfalfa seed producers should consider application of fertilizers to supply adequate amounts of nutrients lacking in the soil. However, it is still difficult to predict accurately if a profitable alfalfa seed yield response to fertilization would occur, particularly when the soils are testing marginal in some nutrient levels and alfalfa seed yields are often reduced by dry weather conditions and/or frost damage.     

三峡库区土壤营养元素分布特征研究

三峡移民工程中土地资源的合理规划利用需要建立在查清区域土壤营养元素背景及分布特征的基础之上,作者利用多目标地球化学调查方法,通过野外实地调查、大面积系统性采集土壤表层样品、测试分析、数理统计,探讨了三峡库区表层土壤中N、P、K、Ca、Mg、S、B、Fe、Mn、Mo、Cl等植物生长必需元素在不同土壤类型中的含量分布特征,以紫色土为例探讨了不同分布高度、不同坡度、不同植被条件对其元素含量分布的影响。结果表明:石灰土是营养元素最丰富的土壤,黄壤是营养元素最低的土壤。母岩对土壤元素分布影响明显,灰岩母岩区土壤营养元素最丰富,砂岩母质区土壤养分元素含量最低;同为碎屑岩类的泥岩、粉砂岩、杂砂岩、砂岩母岩区的土壤相比,泥岩类母岩区的土壤养分元素含量相对较高,粉砂岩母岩区土壤养分元素含量居于泥岩与砂岩母岩区土壤之间。随紫色土分布区地形坡度变化,紫色土Ca、Mg、K元素含量无规律性变化,但随地形坡度变缓,N、S、Mo含量明显增高,Fe、Mn、P含量有增高的趋势;随海拔高度降低,紫色土P、S含量增高,Mn、Mo含量有增高的趋势,而其他元素含量无规律性变化。紫色土在相同的母质、气候及相似的地貌条件下,植被覆盖类型不同,土壤中不同元素分异特征差异明显。总体来说,土壤类型是土壤元素分布的主要控制因素,不同土壤类型的元素含量差异十分显著;不同母质来源的土壤元素差异性显著;紫色土的元素分布除受土壤类型控制外,还受地形坡度、高度、植被条件等其他因素的影响,但不同元素受影响的因素及程度不同。     

Effect of potassium,sulfur, boron,and molybdenum fertilization on alfalfa production and herbage macronutrient contents

An established two‐year‐old stand of ‘Apollo’ alfalfa (Medicago saliva L.) was used to determine the alfalfa yield and macronutrient contents response to potassium (K), sulfur (S), boron (B), and molybdenum (Mo) fertilization under a high yield environment. A split, split block field design was used with nine micronutrient treatments (0, 50, and 100 g Mo ha^‐1 and 0, 1, and 2 kg B ha^‐1) in a factorial arrangement (3²) as the subplots and three K levels (150, 300, and 600 kg K ha^‐1) as the main plot in three replications. Two levels of S (0 and 240 kg S ha^‐1) fertilization were applied in strips across the main plots (K levels) resulting in the split, split block design. Alfalfa yield and macronutrient contests were determined. Increased in K or S rate increased K contents of the plants, however, the differences between the K or S rates were not significant and B or Mo application did not have a marked effect on alfalfa K levels. Alfalfa calcium (Ca), magnesium (Mg), or phosphorus (P) content was not significantly affected by K, S, B, or Mo fertilization. Potassium, S, B, or Mo fertilizer application also did not have a marked effect on alfalfa yield during this study. Combinations of K, S, B, and Mo fertilizer had variable effects and the effects were dependent on the combination of fertilizer, sources, and levels. With a few exceptions, there was lack of alfalfa yield and nutrient contents response to K, S, B, and Mo applications which was due to the effect of low available soil moisture as a result of low incident rainfall during the study on these nutrients availability, uptake, and alfalfa growth.     

灌溉水质对苜蓿早期生长及养分吸收的影响

采用盆栽试验方法,设计7种不同灌溉水质对苜蓿（Medicago sativaL.cv‘.Algonquin＇）进行灌溉处理,包括：清水灌溉（F）、再生水灌溉（R）、等营养水灌溉（E）、清水和再生水交替灌溉（T）、再生水和清水1∶1混合灌溉（FR）、再生水和清水1∶2混合灌溉（F2R）、再生水和清水2∶1混合灌溉（2FR）。研究结果表明,与清水灌溉（F）相比,再生水灌溉（R）可以明显提高苜蓿的株高和侧枝数水平;交替灌溉（T）和混合灌溉（2FR）对提高苜蓿干草产量作用明显;各灌溉水质对苜蓿叶茎比、根冠比和根系活力的影响都是暂时性的,长期进行灌溉影响不显著;混合灌溉（FR、F2R、2FR）和再生水灌溉（R）会提高苜蓿体内氮、钙和镁的含量,而对钾的含量没有影响,苜蓿体内磷的含量随各灌溉水质中磷含量的增加而减小。     

肥料重金属含量状况及施肥对土壤和作物重金属富集的影响

本文对肥料中重金属的含量状况以及施肥对土壤和农作物重金属累积影响的研究进展进行了系统分析和总结。过磷酸钙中锌（Zn）、 铜（Cu）、 镉（Cd）、 铅（Pb）含量高于氮肥、 钾肥和三元复合肥,有机-无机复混肥料中的Pb含量高于其他化肥。有机肥如畜禽粪便、 污泥及其堆肥中的重金属含量高于化肥,猪粪中的Cu、 Zn、 砷（As）、 Cd含量明显高于其他有机废弃物,鸡粪中铬（Cr）含量高;污泥和垃圾堆肥中Pb或汞（Hg）含量高。商品有机肥Zn、 Pb和镍（Ni）含量高于堆肥,Hg含量高于畜禽粪便。多数研究表明,氮磷钾配施与不施肥相比土壤Cd和Pb含量增加,施用有机肥比不施肥提高土壤Cu、 Zn、 Pb、 Cd含量。施用化肥对农作物重金属富集的影响不明确,而施用有机肥可提高作物可食部位Cu、 Zn、 Cd、 Pb 的含量,影响大小与有机肥种类、 用量、 土壤类型和pH以及作物种类等有很大关系。在今后的研究中应着重以下几个方面, 1）典型种植体系下土壤重金属的投入/产出平衡; 2）不同种植体系下长期不同施肥措施对土壤重金属含量、 有效性影响的动态趋势; 3）典型种植体系和施肥措施下土壤对重金属的最高承载年限; 4）现有施肥措施下肥料中重金属的最高限量标准。