Fertigation Strategies to Alleviate Fertilizer Contamination Generated by Tomato Crops under Plastic Greenhouses

Abstract

The rapid development of greenhouse horticulture has brought about a dramatic increase in the nitrate pollution of aquifers. The optimization of nitrogen application is an important tool to minimize nitrogen losses. The objective of this research was to assess the effect of different fertigation strategies, based on the reduction of the nitrogen applied and the use of a percentage of NH4+ as a nitrogen source, on the decrease in the environmental impact caused by the traditional system, as well as to evaluate if this is compatible with a high fruit yield (considering quantity and quality). Lycopersicum esculentum Mill cv. Forteza plants were grown in a polyethylene greenhouse. Tomato yield and quality were evaluated, along with leachates, which were collected by means of rigid plastic lysimeters. The proposed strategies did not reduce fruit yield. However, the reduction in the nitrate applied caused firmness and °Brix decrease, together with a diminution in titratable acidity until 124 days after transplanting. Nevertheless, these effects were not observed with the replacement of some of the NO3− by NH4+. The reduction in fertilizer inputs significantly improved water and nutrient (N, P and K) use efficiency. The treatment with NH4+ improved K use efficiency, compared to the conventional treatment, but P decreased. The highest NO3− and K leaching was detected in the traditional treatment.

Effect of Drip Irrigation and Fertigation on Soil Water Dynamics and Productivity of Greenhouse Tomatoes

“…Drip-based fertigation provides a scope of varied applications of nutrients at different crop growth stages [13]. Moreover, the nutrients' application through fertigation with frequent intervals leads to constant nutrient availability [14,15].…”

Optimizing Tomato Cultivation: Impact of Ammonium–Nitrate Ratios on Growth, Nutrient Uptake, and Fertilizer Utilization

“…An adequate potassium supply is beneficial for tomatoes to resist the support demands of higher yield and improve quality [42]. Plant uptake of both nitrogen and phosphorus increased with the increase in the ratio of ammonium fertilizer, and A75N25 fruits had the highest nitrogen and phosphorus accumulation, indicating that application on a nitrogen mass ratio of ammonium nitrogen to nitrate nitrogen of 75:25 is conducive to the accumulation of nitrogen, phosphorus nutrients, and improving the utilization rate of nitrogen and phosphorus in tomatoes, thus reducing the environmental hazards caused by the loss of nitrogen and phosphorus during the cultivation of tomatoes in facilities [43,44].…”

Optimizing the Nitrogen Use Efficiency in Vegetable Crops

“…Optimize N application rates based on crop demand Improved NUE [27,82,164] Selection of adapted crop varieties Potato and lettuce germplasm; Selection for roots systems with improved N uptake [124,165,166] Controlled-or slow-release fertilizers Utilizing nitrification inhibitors, which is not cost-effective in some systems [24,68,81,167,168] Combined use of organic and chemical fertilizers Improved NUE, soil fertility, and use of local resources [27,169] Placement of fertilizers Field placement including subsurface drip fertigation [24,81,164,170,171] Planting density, spacing Spacing x N response interaction, onions, tomato [172][173][174][175] Plasticulture systems and fertigation Improved NUE [65,158,170,176,177] Timing of application to synchronize with crop uptake demand Tomato, onion, including split applications [19,23,45,58] Precision farming Assessment of yield variations across a field; N status monitoring systems; may not be cost-effective in some systems or for small-scale production [159,178,179] Grafting Improved NUE, melons, tomato [26,125,180]…”