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Contreras J.I.,Institute of Research and Training in Agriculture and Fisheries IFAPA | Lopez J.G.,Institute of Research and Training in Agriculture and Fisheries IFAPA | Lao M.T.,University of Almeria | Eymar E.,Autonomous University of Madrid | Segura M.L.,Institute of Research and Training in Agriculture and Fisheries IFAPA
Communications in Soil Science and Plant Analysis | Year: 2013

As a consequence of increasing water demand, lack of natural water resources, and use of high amounts of fertilizers in the greenhouse crops in arid and semi-arid areas, the use of reclaimed municipal wastewaters is a valuable option, although the knowledge of plant nutritional requirements becomes more important to avoid imbalances caused by the nutrients present in reclaimed wastewater and to attain efficient nutrient use. An experiment was conducted with greenhouse-grown sweet pepper (Capsicum annuum L. var. Aifos) on a sand-mulched sandy loam soil and fertigation with recycled municipal wastewater and inorganic fertilizer treatments. Five treatments were applied: control with no nitrogen (N) or potassium (K) supplied (N0K0) and four different doses of N and K as the mean elements with possible imbalances: N1K1, N1K1.5, N1.5K1, and N1.5K1.5. N1K1was the recommended rate under local conditions (125 kg N ha-1 and 193 kg K ha-1). Eight plants per treatment were collected at five growth stages (0, 56, 84, 113, and 155 days after the seedling transplant, DAT). Dry matter (DM) and N, phosphorus (P), K, calcium (Ca), and magnesium (Mg) concentrations in fruit, leaf, stem, and pruning wastes were measured for each sampling date. For all treatments, the period of largest extraction of nutrient by plant occurred from 113 to 155 DAT, which coincides with the greatest accumulation of dry matter. Plant nutrient distribution showed that fruit is the largest sink of N, K, and P. The NK levels showed no effect on DM and nutrient uptake in the periods of vegetative growth, fruiting, and fruit growth. Nutrient uptakes by the plant were not affected by NK level applied. The NK rates could be lowered significantly without reducing DM and nutrient total uptake by plant during vegetative growth, flowering, and early fruit development periods, when using reclaimed municipal wastewater. The fertigation with greater rates of N and K for the harvest period can be considered as an adequate and sustainable procedure to grow greenhouse pepper. © 2013 Copyright Taylor & Francis Group, LLC. Source


Contreras J.I.,Institute of Research and Training in Agriculture and Fisheries IFAPA | Eymar E.,Autonomous University of Madrid | Lopez J.G.,Institute of Research and Training in Agriculture and Fisheries IFAPA | Lao M.T.,University of Almeria | Segura M.L.,Institute of Research and Training in Agriculture and Fisheries IFAPA
Communications in Soil Science and Plant Analysis | Year: 2013

The use of regenerated water (RW) for irrigation of horticultural crops in the Mediterranean area could contribute to reduce fertilizer inputs, water consumption, and contamination of the environment. The nutrient content of RW and nutrient demand by crops needs to be match to achieve these benefits. This work studies the influence of different levels of nitrogen (N)- potassium (K) fertigation with purified wastewater obtained from Almería city, Spain, on yield, fruit quality, and macronutrient uptake of pepper plants. The experiment was conducted in a polyethylene greenhouse with pepper cv. Aifos, grown on a sand-mulched sandy loam soil using trickle irrigation. The experimental design was randomized blocks with four replicates. Six treatments were applied: two unfertilized controls (RW and ground water, GW) and four NK levels with regenerated water, RW (N1K1, N1K1.5, N1.5K1, and N1.5K1.5). N1K1 is the recommended rate under local conditions, and 125 kg N ha-1 and 193 kg K ha-1 respectively are average nutrient concentrations in fertigation of 9.8 mM N (NO3 - + NH4 +) and 5.4 mM K. The results showed that production parameters were equal in unfertilized RW irrigated plants compared to those irrigated with GW water, both resulting in low commercial production. Fertigation with N1K1 produced yields similar to the RW control. Significant increases in marketable yields, number, and weight of fruit were recorded with N1.5K1.5, N1K1.5, and N1.5K1 rates compared to RW control. The NK level had no effect on fruit quality attributes (pH, fruit firmness, total soluble solids, and titratable acidity of fruit). Nutrient uptake of plants followed the same order in all treatments: K > N > calcium (Ca) > magnesium (Mg) > phosphorus (P). The treatment N1.5K1.5 showed the greatest uptake of N and P, and K uptake was similar to N1K1.5 and N1.5K1 treatments. © 2013 Copyright Taylor & Francis Group, LLC. Source


Contreras J.I.,Institute of Research and Training in Agriculture and Fisheries IFAPA | Plaza B.M.,University of Almeria | Lao M.T.,University of Almeria | Segura M.L.,Institute of Research and Training in Agriculture and Fisheries IFAPA
Communications in Soil Science and Plant Analysis | Year: 2012

The Mediterranean area has been experiencing an extensive development of intensive horticulture, with a majority of that located in arid and semi-arid regions with limited water resources and poor water quality. One of the most important greenhouse vegetable crops is melon. This article studies the effects of different nitrogen-potassium (N-K) fertilizers applications and two types of irrigation water on yield and nutritional behavior of melon crop Cucumis melo L. (var. cantalupensis Naud. Alpes). The trial was conducted during two cycles under Mediterranean greenhouse conditions, on sandy mulching soil. The experimental design was bifactorial: NK fertigation and water quality, with three nutrition levels and two water qualities [MS with electrical conductivity (EC) = 0.6 dS m -1 and HS with EC = 2.3 dS m -1]. During the first cycle, the fertigation levels were F 1 (50% NK), F 2 (100% NK), and F 3 (125% NK). In the second cycle, the fertigation levels were F 2, F 4 (125% N and 150% K) and F 5 (180% N and 220% K). Treatment F 2 was the recommended total doses (220 kg N ha -1 and 355 kg K ha -1). The increase in the NK concentration of the nutritive solution produced a rise in commercial production. The salinity of irrigation water did not affect marketable yield but had an effect on the fruit size, which was compensated for by an increase in the amount of fruit produced. Dry-matter production, N, and K uptake by plant (g m -2) were evaluated in the first and second trials. Salinity and NK nutrition levels significantly affected (P < 0.05) dry matter and N and K uptake by melon plant. Nitrogen and K uptake present interesting correlations with production and with each other, as established by mean regression analysis. © 2012 Copyright Taylor and Francis Group, LLC. Source


Jimenez S.,University of Almeria | Plaza B.M.,University of Almeria | Segura M.L.,Institute of Research and Training in Agriculture and Fisheries IFAPA | Lao M.T.,University of Almeria
Communications in Soil Science and Plant Analysis | Year: 2012

The improvement of water and nutrient efficiency leads to a production model that is more sustainable with less water, fewer fertilizer inputs, and less environmental damages. High-technology fertigation equipment permits high precision in the nutrient solution application. Besides, the field measurement of soil water content by tensiometers and the extraction of soil solutions by suction cups allow a dynamic methodology management in agreement with real crop requirements. This trial was carried out to compare this dynamic fertigation management method (using tensiometers and suction cups) for tomato crops (Lycopersicum sculentum Mill. Forteza) under Mediterranean greenhouse conditions with other methods: the local traditional model, based only on technical consulting, and the classical model, by means of estimation of Kc and nutrient extractions references. The parameters studied were tomato yield, water, and fertilizer amounts applied during the cultivation as well as water-and fertilizer-use efficiency. The water used to prepare the nutrient solution was classified as C 4-S 3 following the Riverside classification system. Plants were grown from 15 August to 20 April. The results show that the supply of fertilizers during the cultivation has been significantly lower with classical and dynamic models. Dynamic method shows greater efficiencies for all the elements, except for potassium, and also decreases the water consumption, not affecting total yield. © 2012 Copyright Taylor and Francis Group, LLC. Source


Contreras J.I.,Institute of Research and Training in Agriculture and Fisheries IFAPA | Bueno I.,Institute of Research and Training in Agriculture and Fisheries IFAPA | Lao M.T.,University of Almeria | Segura M.L.,Institute of Research and Training in Agriculture and Fisheries IFAPA
Communications in Soil Science and Plant Analysis | Year: 2013

The experiment was conducted in two polyethylene greenhouses located in Almería (Spain) with Mantra green bean crop (Phaseolus vulgaris ssp. volubilis), on a sand-mulched loam soil with trickle irrigation. The experimental design was two factorial with four replications per treatment. The treatments applied were two crop systems, organic (OCS) and integrated (ICS), and two organic-matter levels of soil, 1.0% (low organic-matter soil, LOMS) and 2.5% (high organic-matter soil, HOMS). Nitrogen (N) and potassium (K) were applied by fertigation, and total levels were 68 kg N ha-1 and 107 kg K ha-1 following Regulation (CEE) 2092/91 (Organic Crop System) and Specific Regulation of the Junta of Andalusia (Spain) BOJA 10/01(Green Bean Integrated Crop Production). Total N, phosphorus (P), K, calcium (Ca), and magnesium (Mg) were determined in different plant fractions (fruit, leaf, and stem). Nutrient extraction by plant was significantly greater under ICS (111 kg N ha-1, 36 kg P ha-1, 130 kg K ha-1, 96 kg Ca ha-1, and 30 kg Mg ha-1) than under OCS (78 kg N ha-1, 22 kg P ha-1, 83 kg K ha-1, 71 kg Ca ha-1, and 22 kg Mg ha-1). Extracted nutrient levels did not show significant differences between organic-matter treatments. Nutrient-use efficiency was similar under all treatments. Also the N and Ca patterns between organs were unaffected by treatments, but P, K, and Mg distribution patterns among organs were affected by treatments. In general, N fruit and leaf extractions were similar (around 40%) and greater than N stem. Phosphorus leaf extraction was greater than in stem and fruit. Calcium and Mg extractions were the greatest in leaf (70% and 50%), intermediate in stem (20% and 30%), and the lowest in fruit (10% and 20%). Potassium fruit extraction under ICS was significantly greater (39%) than OCS (35%), whereas K stem extraction under OCS was greater (40%). Similar distribution patterns were found for organic-matter level. Potassium fruit extraction under HOMS was greater, whereas K stem extraction was greater under LOMS. © 2013 Copyright Taylor & Francis Group, LLC. Source

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