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。     

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。     

不同滴灌方式对棉田土壤盐分的影响

采用田间抽样调查分析的方法,研究了不同滴灌方式对新疆棉田土壤盐分的影响。结果表明,采用滴灌施肥8年后,0-100cm土体土壤总盐平均质量分数膜下滴灌比地下滴灌高10．98％;在20cm以上土层,土壤总盐平均质量分数地下滴灌比膜下滴灌高出23．35％;在60-100cm土层,土壤总盐平均质量分数膜下滴灌比地下滴灌高出85．99％。造成不同灌溉方式下土壤总盐质量分数差异的主要离子为Cl-和Na＋。膜下滴灌条件下,土壤Cl-和Na＋的质量分数较高。试验区采用地下滴灌时,应防止地表盐分的积累,同时,应结合喷灌或地面灌溉,解决棉花苗期的土壤水和盐的问题。     

水肥一体微喷带施肥均匀性试验研究

为探究水肥一体化微喷带大田施肥均匀性及影响因素,通过两种长度微喷带在4种首部工作压力下肥液浓度测定试验,分析沿微喷带方向与垂直于微喷带方向的肥液浓度变化规律。结果表明:使用微喷带进行田间施肥时,微喷带铺设长度对肥液浓度均匀性影响不大,但随着沿程压力降低,施肥量会随灌水量的降低而减少;垂直于微喷带方向的肥液浓度在靠近微喷带的位置点变化平缓,沿微喷带方向肥液浓度小幅度减小。不同的铺设长度存在不同的最优首部工作压力,微喷带铺设长度为20 m、首部工作压力为40 kPa左右时和铺设长度为40 m、首部工作压力为28 kPa左右时,肥液浓度变化相对平缓。微喷带与比例式施肥泵配套使用进行水肥一体化灌溉时,肥液均匀性较高,实际使用时应进行合理配置并设置适宜的首部工作压力。     

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.     

全球环境压力下的增值肥料发展策略

世界经济繁荣造成的富裕阶层对生活的更高要求,成为全球环境压力的主因。生产生物燃料,增加了耕地的产出强度。利用尽可能少的耕地生产更多粮食的强化栽培是现代农业的必然趋势。为此,提出了基肥以有机肥为主,以枸溶性化学肥料为辅,添加多种有益微生物;追肥以新型非水溶性作物营养源的灌溉施肥,提供大量营养元素的肥料发展策略。     

基于PLC的自动化施肥灌溉系统设计

介绍一套在温室条件下实现自动灌溉施肥的微灌系统,该系统以PLC为核心,通过传感器反馈的温室实时信息自动或手动进行灌溉施肥,同时使用变频器达到恒压灌溉的目的,系统的实时监控、数据查询等通过MCGS实现,这对节水灌溉技术的发展起到了一定的推动作用.