Short Description of the technology – General

 

Specialised Decision Support Systems (DSSs) are effective tools to optimise nutrient and irrigation management of vegetable crops. User-friendly DSSs can prepare detailed plans of nutrient and irrigation recommendations for individual crops. The recommended amounts of nutrients are adjusted to the specific requirements of a particular crop, and consider nutrients supplied by the soil as indicated by recent soil analysis and field history. Similarly, the irrigation recommendations are crop and site specific. For both nutrient and irrigation recommendations, feedback from soil monitoring can be used to adjust and further optimise the recommendations.  In the case of soil using soil testing, and for irrigation using soil moisture sensors.

 

Three different DSSs for use with soil-grown vegetable crops are described subsequently. They are the SOIL NUTRISENSE and VegSyst-DSS DSSs that provide nutrient recommendations, and the Virtual Lysimeter that provides irrigation recommendations.

 

1. SOIL NUTRISENSE

 

Short Description of the technology

One DSS developed by ECONUTRI is the SOIL NUTRISENSE, which can be used to provide full fertilization recommendations tailored to the specific needs of any crop and readjust these during the cropping period based on an actual soil analysis. SOIL NUTRISENSE has been developed by the Laboratory of Vegetable Production of the Agricultural University of Athens to support growers cultivating vegetables in the soil, either in greenhouses or in open fields. This DSS is online available at https://nutrisense.online.

SOIL NUTRISENSE recommends a composition of the fertigation solution tailored to the standard requirements of any particular crop species, taking into consideration the climatic conditions, the mineral composition of the raw water used for its preparation, and the available equipment. This recommendation is based on standard literature recommendations. When a soil analysis is available, the SOIL NUTRISENSE modifies (readjusts) the standard recommendation taking into consideration the results of the soil analysis.

 

Innovative Features

The use of DSS to control crop fertilization is not novel, as this has been proposed also in the past by several investigators. Also, the standard recommendations and some basic algorithms originate from previous literature sources. However, SOIL NUTRISENSE is novel in its structure as a specialized software, which comprises a series of novel algorithms developed on the basis of a holistic approach. These algorithms are fed with data originating from water and soil analysis, as well as with information concerning the climatic conditions and the plant developmental stage.    

 

Type of Contribution

The use of DSS to design and monitor the supply of nutrients via fertilization in vegetable crops can substantially restrict nutrient losses due to overfertilization while ensuring or even improving crop yield. Thus, this technology addresses the expected impact 2 as stated in the Grant Agreement (balanced N/P flows well within safe ecological boundaries at EU and Associated Countries, regional and local scale, contribute to restoring ecosystems).

 

Benefits for farmers, the industry, and the environment

The major objective of SOIL NUTRISENSE is to harmonise the nutrient supply through fertigation with the nutrient demand, thus restricting overfertilization, and concomitantly effectively controlling pollution of water resources with N and P. Moreover, by optimizing the nutrient management of soil-grown crops, SOIL NUTRISENSE supports the economic sustainability of the growers due to increased yield production and reduced fertiliser consumption. A lower input of synthetic fertilisers also leads to energy saving by the fertiliser industry, thereby contributing to reduction of CO₂ emissions.

 

 

2. VEGSYST-DSS

 

Short Description of the technology

The VegSyst-DSS is a DSS being developed in the ECONUTRI project. It provides crop- and site-specific fertiliser recommendations for vegetable crops grown in greenhouses in the Mediterranean region. The VegSyst-DSS provides N, P, K, Ca and Mg recommendations for tomato, pepper and melon, and N recommendations for cucumber, watermelon, eggplant and zucchini. It also calculates irrigation requirements for all of these species. The nutrient recommendations are provided both as rates (kg/ha) and as concentrations to apply in nutrient solutions to fertigated vegetable crops. VegSyst-DSS calculates daily recommendations, which for practical use are presented for longer periods, e.g., nutrients concentrations for 4-week periods. 

VegSyst-DSS has been developed by the Crop Nitrogen and Irrigation Laboratory of the University of Almeria, Spain to support growers and advisors cultivating vegetables in soil in Mediterranean greenhouses in south-east Spain. Studies in Italy, Greece, Türkiye and Tunisia suggest its general suitability for the Mediterranean Basin.

A web-based program and Apps (iOS and Android), in Spanish, are freely available at https://vegsystdss.es/web/. It is presented there as the VegSyst-DSS Suite; what is reported here is the Greenhouse component. There is also an open field component. An earlier version of VegSyst-DSS, for greenhouse crops, is available in English, Turkish and Spanish on the web page https://w3.ual.es/GruposInv/nitrogeno/index.shtml. The equations and calibration factors are fully described in a number of articles published in leading scientific journals. These articles provide detailed descriptions of the VegSyst-DSS, and of the calibration and validation of the component VegSyst simulation model.

 

Innovative Features

VegSyst DSS has several innovative features:

• It simulates expected daily crop nutrient by as the product of simulated dry matter production and simulated nutrient content. Cropping dates and expected climate are considered using a data base of long-term climatic data within Mediterranean greenhouses
• Nutrient supply from the soil is considered
• Nutrient use efficiency by the crop is considered
• While based on science, the DSS and its component VegSyst simulation model have been developed using a minimalistic approach to reduce as much as possible data entry

There have been several DSSs developed to provide nutrient recommendations for vegetable crops. None of these have been developed specifically for vegetable crops grown in Mediterranean greenhouses, which for example requires specific equations for reference evapotranspiration and crop coefficient values. Also, the minimalistic approach is unusual in that the only data used and calculations made are those required for making nutrient and irrigation recommendations, and nothing more. For example, the DSS does not estimate yield or nutrient losses.

 

Type of Contribution

This DSS provides nutrient recommendations to vegetable crops that consider the crop demand and the soil nutrient supply. This results in reduced applications of mineral fertiliser and appreciably reduced losses of nutrients (e.g. N and P) to the environment, while ensuring crop yield.

This technology addresses expected impact 2 of the ECONUTRI project as stated in the Grant Agreement (balanced N/P flows well within safe ecological boundaries at EU and Associated Countries, regional and local scale, contribute to restoring ecosystems).

 

Benefits for farmers, the industry, and the environment

The major objective of VegSyst-DSS is to match nutrient supply through fertigation crop nutrient demand after considering nutrient supply from the soil.  Doing so reduces fertiliser application, farmers’ costs and nutrient losses to the environment. The latter appreciably reduces contamination of water resources from fertiliser use in vegetable production.

Additionally, lower applications of mineral fertilisers also result in energy saving by the fertiliser industry, thereby contributing to reduced CO₂ emission.

 

 

3. VIRTUAL LYSIMETER

 

Short Description of the Technology

Wageningen Research (WUR) has developed a virtual lysimeter (VL) to prevent over-irrigation and by this reduce the losses of nutrients and PPPs to ground- and surface water. The VL helps soil-bound growers to manage their emission of water and nutrients to the soil by steering irrigation by the plant need and the water balance in the soil. The VL uses climate computer inputs to calculate crop evapotranspiration, it reads irrigation, and it calculates the movement of water through the three sampled soil layers. To do this; soil is sampled across three soil layers of thirty centimeters, the static parameters of the greenhouse related to construction and operation are specified, and the climate computer is connected to the VL. It has been validated with Chrysanthemum and organic vegetable growers as part of previous projects. This technology is being advanced from TRL 6 to TRL 8-9 as part of ECONUTRI work package 3 task 2.1. The end result is that growers will be able to enroll in the VL and manage their soil water balance as an offering from a commercial crop advising company.

 

Innovative Features

The Vl is one of the first practical tools that enables growers to get insight into their irrigation strategy. The key challenge of the VL is maintaining grower engagement to use this new source of information. Once a grower has been connected and had a thorough explanation of the tool, usually through an in person visit to the grower, then they typically are not yet fully engaging in the VL further. To address this, a monthly report has been made that shows growers who input their crop cycles to the VL their past months’ soil water balance. In addition to the report, the VL has been made into an externally accessible API whereby advising companies can connect the growers directly to the VL through their own crop advising tools. The first company will connect with the API in the course of the project. Advisors are used often and well trusted in the Dutch horticulture industry; therefore, WUR is considering placing more emphasis on making advisors familiar with the VL and disseminating the understanding and use of the tool to growers to increase its use and impact.

 

Type of Contribution (e.g., reduction of nutrient losses, greenhouse gas emissions, etc.)

The contribution of the VL to enrolled growers is the reduction of water (and nutrients in the water solution) to the ground water. When the soil water buffer is carefully managed, the emission is reduced to near-zero with no effect on crop growth and productivity.

 

Benefits for farmers, the industry, and the environment

The benefit for the grower is primarily environmental – reduction of emissions to the ground water effects Dutch surface water quality. However, the elimination of these emissions into the ground water, surface water, and waterways in the Netherlands is required by 2027 and the VL can help soil-bound growers comply with new rules and demonstrate to regulators their compliance.

By optimizing nutrient use, the DSS plays a key role in reducing nutrient losses to the environment, particularly under the guidelines of the Nitrate Directive. As well as show the different requirements of nutrition if practices, like using the extra organic matter from production in addition to the soil, are implemented.