El protected crop of berries in the province of Huelva It is cultivated in sandy soils, poor in organic matter, low EC, with little water and nutrient retention power, and with very low interaction with nutrients. As a background subscriber or previous amendments of the soil, a low application is made, for this type of soil, of organic fertilizer or normally manure manure, in quantities that have little influence on the physical properties of the soil. In mineral form, a small amount is also applied, since its effect lasts very little, due to the texture of the soils and the washes that are produced by the volumes of water that are applied to build the ridges and to maintain their structure before of the plantation. In addition, irrigation water is generally used, with very low salinity, which also does not provide nutrients. It is irrigated with high frequency and significant volumes of water, which imply a significant risk of nutrient laundering. In a way, it can be considered as a hydroponic soil crop. Therefore, the tendency in the area is to pay for the proportional management system, in which the amount of fertilizers is linked to the volume of irrigation water applied, and not to the surface or number of plants. The contribution of the nutritive solution comes to us due to the water requirements of the crop and not because of the theoretical needs.

In general, we apply the nutrients at the rate that the crop needs them, following the absorption curve of each element, to avoid losses, leachate, and contamination. We manage balances between optimal nutrients to avoid incompatibilities and increase absorption efficiency at all times. For this adjustment we need a detailed knowledge of the demand of nutrients of the variety, of the soil, of the water, irrigation system, strict control of the irrigation, CE, climatic aspects, productive factors.

Berries have a special interest, as it generates wealth and employment, and has the obligation to be respectful of its surroundings, the Doñana National Park. Therefore, it is necessary to find management tools or indicators to assess the management of the water-fertilizer binomial, and help improve the application of fertigation.

In Berries in protected systems, irrigation management is widely used based on knowledge and control of climatic parameters and soil moisture (Gavilán). However, nutrition control systems have had a lower degree of development. Therefore, Gat Fertiliquidos, a manufacturer of liquid fertilizers, began to study its fertilization, in order to help farmers to fertilize more efficiently.

Summary

For the control of nutrition in berries, the Agronomic Department of Gat Fertiliquidos has been conducting follow-up trials of fertilizers in all Berries, seven follow-up trials and comparison of fertirrigation in strawberry cultivation, 2012 to 2016, grown in three commercial plots . Fertirrigation test of a rod raspberry crop on a plot of the experimental farm "El Cebollar" Moguer (Huelva), belonging to IFAPA. Cranberry fertirrigation tests in two commercial farms and in the experimental farm "El Cebollar" IFAPA.

"A continuous supply of balanced nutrients is essential for each stage of plant development ”

The objectives were: to know the needs and efficiency in the use of Berries nutrients in Huelva conditions, evaluate the productivity of the nutrient solution, determine the efficiency in the use of the subscriber and relate it to the efficiency in the use of water of irrigation. To generate knowledge about the pre-harvest factors of the crop that optimize its post-harvest quality, to try to improve the quality of the fruit without damaging its production, by increasing salinity with fertigation management.

 Materials and methods

All volumes of irrigation water and fertilizers from both irrigation and available and drainage or leachate soil solutions were measured, with analytical monitoring during all campaigns. Analytical monitoring was carried out with sampling every 15 days of the Fertilizer Solution (SF), soil solution (SS) with suction probes, drainage or leaching solution (SD) with drainage lysimeters buried in the soil. Vegetable analysis of leaf samples and the productions obtained.

Results and Discussion

The concentration of salts in soil solution and drainage solution were very similar to those of the dropper, There is no interaction or retention on the ground. There were no accumulations of salts in root zones in treatments with different volumes of fertigation. Small differences appeared in favor of the intermediate entry, which presented greater efficiencies and use in the use of fertilizers. However, this advantage is not appreciated in sheet analysis or production. Statistically there were no significant differences in the productions obtained. However, trends were observed, with higher productions when higher doses were applied.

The average efficiency value of the subscriber is around 0.3, higher than the value of 0.1 assumed by Aldaya et al. (2010) for the calculation of the Gray Water Footprint in the strawberry crop of Huelva.

We have evaluated the speed of displacement of the Nitrogen in the soil and the leached nitrogen curves are displaced about 40 days from the N contributed, which implies a distance of displacement of the N from the dripper to the bottom of the lysimeter of 0,75 m. The rate of nitrogen displacement is therefore 0,56 m month-1.

Berries are crops sensitive to salinity, which can lead to a reduction in fruit production. However, salinity can provide greater organoleptic and / or functional fruit quality. These Strategies were based on the increase in salinity in the nutrient solution provided through irrigation, applied at the time of cultivation in which it has already reached vegetative development and begins the fattening of the first fruits.

In raspberry application of fertirrigation above the values ​​calculated optimally do not have an associated increase in yield. The productivity values ​​of the irrigation water that obtains the best production are 13,0-11,3 kg m^-3. Likewise, the highest efficiency of the fertilizer with respect to production was offered by the optimal treatment.

In blueberries, the best fertirrigation yields are obtained with optimum pH control and good soil aeration and drainage. Good balance between nutrients and available

Therefore, a continuous supply of balanced nutrients is essential for each stage of plant development, supplied at the rate that can be absorbed without being stored in soil and avoid losses. In these cases, optimal management of irrigation, EC and pH is very important.