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In order to answer the question to what extent the salt tolerance of agricultural crops is growth stage dependent, a literature study has been carried out. For the plant’s reaction to salt in the root zone, various mechanisms are responsible. They can be summarized in an osmotic effect and an ion effect, each with their own dynamics. The variability of salt tolerance at successive growth stages can only be addressed qualitatively. The lack of data collected under Dutch growth conditions means that cropwise quantification is not possible, and application in water management is problematic. New experiments are needed to get a finger behind the ‘genesis history’ of salt damage., Om de vraag in hoeverre de zouttolerantie van landbouwgewassen groeistadiumafhankelijk is te kunnen beantwoorden is een literatuurstudie uitgevoerd. Voor de reactie van de plant op zout in de wortelzone zijn verschillende mechanismen verantwoordelijk. Zij zijn samen te vatten in een osmotisch effect en een ioneffect, elk met hun eigen dynamiek. De kennis van verloop van zouttoleranties bij opeenvolgende groeistadia blijkt kwalitatief en fragmentarisch. Het ontbreken van onder Nederlandse groeiomstandigheden verzamelde gegevens betekent dat kwantificering per gewas niet mogelijk -, en toepassing in het waterbeheer problematisch is. Nieuwe experimenten zijn nodig om een vinger te krijgen achter de ‘wordingsgeschiedenis’ van de zoutschade

This report presents a case study of the performance of the irrigation system commonly used in potato production in Northern Algeria, the portable sprinkler system. The aim is to determine water use, water losses and water distribution uniformity. Furthermore, it is evaluated whether the applied irrigation water can be stored in the root zone, and if irrigation applications match with crop water demand. Based on the findings, some recommendations will be given to improve the system. Algeria is among the countries with the lowest renewable water resources per capita in the world, but currently, data and information on irrigation system performance is lacking. In this study, the portable sprinkler system is evaluated by means of field measurements (catch can test, sprinkler discharge measurement, soil moisture measurements) and modelling (CROPWAT 8.0 model). It was found that water losses due to wind drift and evaporation are rather high (36%) compared to values found in literature, whereas the water distribution uniformity was low (DU 34.6% and CU 51.2%), from which it can be concluded that the system performs poorly. Furthermore, it was found that water applications are too high, especially in the beginning of the growing season. The most important recommendation to improve the performance of the irrigation system is an alternative irrigation schedule, adapting the timing and duration of irrigation events to crop water demand and the water storage capacity of the root zone.

While Algeria is among the countries with the lowest renewable water resources per capita in the world, agriculture accounts for 70-80% of the total water use and municipal water use is expected to almost double in the next twenty years. As potato is in Algeria the main irrigated crop and the first vegetable crop in terms of area and production, improving the potato production system and rationalizing the use of water is key to sustain the production in the future and to maintain and enhance food safety. Coherent information of the current potato production system is crucial to improve a system and since this is lacking, we research what is the current situation for potato production in two main production areas of Algeria, in a Mediterranean and desert climate. Through interviews with farmers, other stakeholders and field visits in both areas the current systems are described, analysed on main weaknesses, followed by and advice regarding improvement and implementation of the subsequent project which will be a setup of a demonstration farm to introduce a more productive and sustainable system. It was found that the systems have many points for improvement regarding productivity and sustainability. That both regions have a lack of technology and accurate data of 1) the exact inputs applied, and 2) the exact requirements, especially regarding water supply, lies on the basis of most weaknesses, resulting in rough irrigation, fertilizer and pest management. The main recommendation is to elaborate research of the current system with productivity as focal point to make clear what are the economic advantages for a farmer to adapt the new system. Farmer Field Schools are proposed as a practical and hands-on management approach to implement suggested improvement practices and to introduce a new production system.

Since 2013 the Netherlands Ministries of Economic and Foreign Affairs has been involved in private companies in research and development (R&D) in developing countries. This in a policy going “from aid to trade”. Especially in upcoming markets, R&D is carried out through Public Private Partnerships. Such partnerships not only include R&D organizations in the two countries but specifically also include businesses in both countries. This was to assure a logical flow of material and knowledge by all parties involved. Half of an R&D project is funded by the ministry and the rest is covered by a consortium of companies that contribute in kind and in cash. The policy is aimed at stimulating business development in developing countries and the Netherlands through cooperation and joint R&D. The paper explains how eleven consortia around potato business opportunities were formed, their R&D need was elicited and R&D projects formulated in the Asian countries China, India, Indonesia, Vietnam, Bangladesh and Myanmar, and Ethiopia and Kenya in Africa. In common are fact finding and descriptions of cropping systems, yield gap analysis and value chains in each country. Emphases differ with China looking for an integrated system of field operations, India for optimization of storage and processing, Indonesia to reduce pesticide and nutrient inputs, Vietnam for widening the varietal base, Bangladesh for combating late blight, Myanmar for cultural practices that lead to increased yield, Ethiopia where a potato processing unit is being established and Kenya importing seed potato from the Netherlands. Some content information is given as examples to illustrate the approach and some preliminary conclusion are discussed.

De opwarming van de aarde heeft mogelijk grote gevolgen, die voor een deel moeilijk te voorspellen zijn. Waarschijnlijk zien we in de toekomst meer weersextremen, terwijl meer dan de helft van de bevolking leeft in gebieden die kwetsbaar zijn voor klimaatverandering.

In het Deltaprogramma Zoetwater is het lastig gebleken economische analyses te maken voor de programmering van maatregelen en/of de beleidsmatige afweging rond waterbeschikbaarheid. Een van de knelpunten is het gemis aan inzicht in de droogte- en zoutschade in landbouw en natuur. De zoutschade aan landbouwgewassen is nog niet goed in beeld; er zijn veel getallen in omloop, maar de manier waarop deze tot stand zijn gekomen en/of gerapporteerd is niet eenduidig. Daarom is de tussen 1950 en 2015 in Nederland beschikbaar gekomen informatie geanalyseerd. Het resultaat is specificatie van zouttolerantiedrempels voor 35 gewassen en gewasgroepen, gekoppeld aan het zoutgehalte van beregeningswater.