Pre-plant slow-release fertilization of strawberry plants before fertigation

The advantages of pre-plant fertilization were studied by using a slow-release fertilizer (nitrophoska permanent) with strawberry plants (Fragaria ananassa, cv Chandler) before fertigation. A sandy soil was used in the experiment in conditions of abundant rain. When the slow-release NPK was mixed with soil, the leachate analysis of a glasshouse crop showed a lower loss of N and therefore a lower degree of ground water contamination compared with the traditional NPK fertilizer. However, when the fertilizer in question was placed at 10 cm from the surface, as in the case of ornamental plants, the results were less favourable. Consequently, the slow-release fertilizer mixed with the soil not only increases the N uptake by the plant as well as the leaf and root weight, but it also produces higher yields.Resumen Se estudian las ventajas de una fertilización de fondo del cultivo de fresón, con un fertilizante de liberación lenta (nitrophoska permanent), previa a la fertilización. Se utilizó un suelo arenoso y se reprodujo una alta pluviosidad en los ensayos. En cultivo de invernadero se comprobó, mediante el análisis de drenajes, una menor pérdida de N y por lo tanto menor contaminación de acuíferos, para el NPK de liberación lenta mezclado con el suelo. Sin embargo, cuando este fertilizante se localiza a 10 cm de la superficie como en el caso de plantas ornamentales los resultados son menos positivos. Por tanto, el fertilizante de liberación lenta, mezclado con el suelo, proporciona mayor exportación de N por la planta y mayor peso de hoja y raiz, así como mejores rendimientos.     

Fertigation versus conventional fertilization of flatwoods grapefruit

A four-year field experiment was conducted to compare conventional fertilization by broadcasting granular material with a combination broadcast/fertigation program. The experiment was conducted on mature Ruby Red grapefruit trees in a south Florida Flatwoods grove. The conventional fertilization (CONV) consisted of broadcast applications 3 times per year (Feb/Mar, May/Jun, Oct/Nov). The combination treatment (COMB) had a broadcast application of 33% of the annual N and K₂0 in Feb/Mar followed by the remainder applied as fertigation at 2-week intervals beginning in April. The CONV plots received 33% of the annual N and K₂0 (plus minor elements) during an application in late winter plus additional applications, each with a third of the annual N and K₂0 in the May/June and Oct/Nov time periods. During the four-year period, the COMB trees out-produced the CONV trees in 3 of the 4 years. The 4-year cumulative fresh fruit yield advantage of the COMB trees averaged 4150 kg ha^–1 (108 boxes ha^–1) per year advantage over the CONV program. The cumulative total soluble solids (TSS) produced over four years with the COMB trees averaged 10.9 Mg ha^–1 versus 10.1 Mg ha^–1 for the CONV treatment. The production increases by the COMB treatment over the CONV program represent 8% and 9% advantages for the TSS and fruit yield, respectively. The combination dry + fertigation treatment provided a higher fertilizer use efficiency (greater production for similar application rates) than the conventional dry broadcast applications alone.     

我国水溶性肥料产业发展的机遇与挑战

节水农业的发展、土地流转的加速推进以及基础肥料的产能过剩,极大地推动了我国水溶性肥料产业的发展。从我国水溶性肥料的发展趋势、技术与产品创新途径入手,结合水肥一体化技术推广要求及市场竞争因素分析,介绍了当前水溶性肥料产业发展的问题与机遇,提出农化服务水平是推动水溶性肥料产业发展的关键。     

Olive oil composition as a function of nitrogen,phosphorus and potassium plant nutrition

BACKGROUND: Macronutrients play fundamental roles in processes affecting olive oil productivity and are expected to influence oil composition. A necessary step in optimal nutrient application management for olives is an understanding of the relationship between olive tree nutritional status and oil quality parameters. We studied the independent effects of N, P and K concentrations in irrigation solution on the oil quality of ‘Barnea’ olives by applying a wide range of macronutrient concentrations under highly controlled conditions. RESULTS: Oil composition was significantly influenced by P and N levels, while K levels had only a minor effect. Unsaturation levels were unaffected by the treatments but, within the unsaturated fatty acids, the levels of PUFA increased compared to those of MUFA. Specifically, levels of the MUFA C18:1, polyphenol content and peroxide values decreased while levels of the PUFA C18:3 increased in response to higher doses of N and P. CONCLUSION: Decreased MUFA and polyphenol levels coupled with increased omega‐3 levels demonstrated a potential negative influence on oil profile alongside increased nutritional benefits. The sum effects on oil yield and composition should be considered in designing of nutrient application management strategies for olive orchards. Copyright © 2009 Society of Chemical Industry     

灌溉施肥技术

灌溉施肥技术是灌溉技术与施肥技术的有机结合 ,只有合理统筹运用两项技术才能发挥其最大效能 ;与传统施肥方法相比 ,灌溉施肥技术具有无可比拟的诸多优点 ,但同时也对肥料的制造和使用提出了更高的要求 ,只有全水溶性的肥料才能在微灌系统中成功运用 ,这使得大部分磷肥品种不能用于灌溉施肥 彻底解决灌溉用肥中的磷源问题有利于推动灌溉施肥技术在我国的大面积推广     

畦灌施肥地表水流与非饱和土壤水流-溶质运移集成模拟Ⅱ：模型率定及验证

摘要：利用冬小麦扬花水畦灌施肥试验数据,对构建的畦灌施肥地表与非饱和土壤水流溶质运移集成模型进行率定,基于冬小麦返青水田间试验数据,对该集成模型在不同畦灌施肥模式下模拟的地表水流推进时间、沿畦长土壤体积含水率和硝态氮浓度、畦灌施肥系统性能评价指标值等进行验证。结果表明,模拟结果与田间实测数据的相对误差值和平均相对误差值均小于相应的控制误差,构建的集成模型可用于模拟预测不同畦灌施肥模式下地表和非饱和土壤水流溶质运移转化过程及分布状况,为开展畦灌施肥系统优化设计和性能评价提供了有效的数值模拟工具。     

以非水溶性肥料或矿物进行灌溉施肥的新方法

介绍一种灌溉施肥的新方法。采用非水溶性肥料或矿物(低品位活性磷矿、特殊玻璃网络结构的钙镁磷肥、低交联度硅钙网络冶炼炉渣及活性有色金属矿尾砂等)通过在专利设备——液升式灌溉施肥反应器中加入活化剂反应,就地制备含H2PO4-、Ca2+、Mg2+、Fe2+、Zn2+、Mn2+、BO33-及水溶性硅酸的营养液,可直接用于灌溉施肥或叶面喷施。     

高浓度复合肥在灌溉施肥中对香蕉生长及水肥利用的影响

在海南香蕉主产区进行田间试验,研究了高浓度复合肥(HCCF)对香蕉生长及水肥利用的影响.结果表明:在等肥料成本前提下,HCCF处理香蕉比对照(传统施肥)表现出更好的生长势.单株产量18.32 kg/株,折合产量39.0×103 kg,/hm2,比对照增产8.0％;香蕉果指数比对照增加8个/株,果指长、果指围分别比对照增加11.8％和4.6％;综合经济效益分析,高浓度复合肥处理比对照纯收益增加;高浓度复合肥在灌溉施肥中具有广阔的应用前景.     

Thirty years fertilization and irrigation in Dutch apple orchards: A review

Fertilizer levels increased during the 1960s in The Netherlands because of a move towards all grass orchards in which the grass competed with apple trees for nutrients. During the 70s, many apple orchards kept the soil bare around the trees which lessened the demand for fertilizer. Also the need to avoid storage disorders and improve crop quality prompted a reduction in fertilizer use. Since the late-seventies fertilizer applications have stabilized at a low rate, as a result of the emphasis moving from fruit yield to fruit quality.Due to the prevailing wet weather conditions there was little interest in additional water supply until the mid-seventies. After 1976, an extremely dry year, growers became interested in irrigation. Experiments, in which the fertilizer was broadcast in early spring, showed that additional water promoted shoot growth. Flower-bud formation and therefore production did not always keep pace with the increased vegetative growth. However, fertigation, i.e. adding fertilizer to the irrigation water, not only resulted in strong shoot growth and proper leaf colour, but also in sufficient flower-bud formation. Also with fertigation production was greater than with broadcast fertilization in combination with trickle irrigation.Fertigation may also permit control of the root environment because water and nutrient supply become independent of climatic conditions; this method of fertilizer application may facilitate optimizing the nutrient availability in the root zone, and minimize leaching.     

Principles of fertilizer use for trickle irrigated crops

Under trickle irrigation only a portion of the soil volume around each plant is usually wetted. Typically this is an eliptically shaped volume directly below the emitter. Crop root growth is essentially restricted to this volume of soil and nutrient reserves within that volume can become depleted by crop uptake and/or leaching below the root zone.If nutrients are applied outside the wetted soil volume they are generally not available for crop use. Fertilizer placement is therefore an important consideration for trickle irrigated crops. Thus, applications banded close to the emitters are preferable to broadcast applications. In general, injection of nutrients into the irrigation water (fertigation) gives a better crop response than either banded or broadcast applications. Fertigation gives a flexibility of fertilization which enables the specific nutritional requirements of the crop to be met at different stages of its growth. In comparison with conventional methods of irrigation and fertilization it appears that trickle fertigation can, under some conditions, produce comparable or higher crop yields with substantial savings (of up to 50 percent) in fertilizer useage.Fertilizer materials used for fertigation must be completely soluble in water and must not react with substances in the irrigation water to form insoluble precipitates. An uneven distribution of nutrients within the crop rooting zone occurs under fertigation since immobile nutrients such as phosphate become concentrated around the emitter while mobile ions such as nitrate and potassium move downward and outward with the wetting front and accumulate at the periphery of the wetted soil volume. Plants, however, appear to have the ability to adapt to spatial variability of available nutrients in soils.