Yield gaps and nutrients use efficiency of apple tree (golden delicious/MM106) in the middle Atlas Mountains of Morocco

The main objective of this work was to evaluate use efficiency of nitrogen, phosphorus, potassium, calcium and magnesium in adult apple orchards in the Middle Atlas of Morocco and to establish preliminary reference norms for fertilizing this crop under local conditions. The study was based on soil and leaf analysis and data with regard to farming practices and yield on forty apple orchards (cv. Golden delecious/MM106) where nineteen are growing on silty-clay soil and twenty-one on sandy-loam soil. The results showed significant correlations between leaf content for each nutrient and yield level following polynomial equations, thereby indicating local reference norms for apple leaf analysis. Moreover, correlations were significant between leaf and soil contents that permitted to determine apple needs in nitrogen fertilizer and references norms for soil richness in phosphorus, potassium, calcium and magnesium to obtain yield potential in the study region. However, the found norms are less than International standards because of feebleness of yield level in the study region, largely related to deficient cultural practices adopted by farmers. In addition, investigation of leaf nutrients ratios N/K, N/Ca, K/Ca, K/Mg and Ca/Mg showed that there was disharmony in uptake of these nutrients originating particularly from high soil richness in Ca and Mg. Taking into account these considerations, the found references norms can be applied only under the adopted farming practices. Nevertheless, by improving local practices, reference values may change

Wetland restoration and nitrate reduction: the example of the periurban wetland of Vitoria-Gasteiz (Basque Country, North Spain)

Changes in land use and agricultural intensification caused wetlands on the quaternary aquifer of Vitoria-Gasteiz (Basque Country) to disappear some years ago and nitrate concentration in groundwaters increased very quickly. The Basque Government recently declared the East Sector of this aquifer a Vulnerable Zone according to the 91/676/CEE European Directive. Recently, the wetlands have been restored through the closure of the main drainage ditches, the consequent elevation of the water table and the abondonment of agricultural practices near the wetlands. This is the case of the Zurbano wetland. Restoration has allowed the recovery of its biogeochemical function, which has reduced nitrate concentrations in waters. Nitrate concentrations which exceed 50 mg l–1 in groundwaters entering into the wetland are less than 10 mg l–1 at the outlet. Conditions in the wetland are conducive to the loss of nitrates: organic matter rich wetted soils, clay presence allowing a local semiconfined flow and very low hydraulic gradient. Water quality monitoring at several points around the wetland showed the processes involved in nitrate loss, although some aspects still remain unresolved. However, during storm events, the wetland effectively reduces the nitrate concentration entering the Alegria River, the most important river on the quaternary aquifer

Estimating generalized of global impacts to water quality on soil characteristics in basin of the Great Sebkha of Oran

In basin of the Great Sebkha of Oran, water deficit linked to climate semi-aridity has forced farmers to resort to the use of underground water of poor quality, which considered as the major cause of soil degradation. The alluvial aquifer waters are particularly characterized by higher relatively concentration in dissolved salts when compared them with other aquifers of the same system. Generally, the salinity of the water increases from upstream to downstream in the direction of the Sebkha (Boualla et al. in Water Supply 17(6):1801–1812, 2017). Assessment of soil quality has become the basic work for agricultural sustainable development. The aim of this paper is to evaluate soil properties in great Sebkha of Oran basin. Geo-referred soil samples were collected from ten-component analysis, and different soils were analysed for different physical and chemical attributes. Our study focuses on mineralogical analysis and geochemical prospecting using soil chemical data. Eleven indicators were selected to constitute data to assess the soil quality: sieve analysis, classification, cation exchange capacity, pH, soil organic matter, conductivity, gypsum, nature of the oxide content, nutrients (NO$_{3}$-N, NH$_{4}$-N, PO$_{4}$-P), anions content (SO4$^{2-}$, Cl$^{-}$) and mineralogical analysis. Conclusively, process and mechanism of soil quality need deep research

Understanding the quality of local vineyard soils in distinct viticultural areas: a case study in Alcubillas (La Mancha, central Spain)

The essential features of the soils of a pilot zone in La Mancha (Central Spain), namely the Alcubillas municipability, have been characterized. The soil properties that may contribute to a better understanding of the impact of soil on grape production have also, been evaluated. For this, several soil profiles have been described and analyzed and the profiles have been mapped. The soils are mainly Entisols, Inceptisols and Alfisols, with their evolution controlled by the action of a xerophytic Mediterranean climate. Most of these soils have a loamy clay texture, with medium clay contents and sufficient nutrient contents (despite the low content in organic matter 1.39% and 1.04%, and the high concentrations of calcium carbonate 23.7% and 26.9% in the surface and subsurface horizons, respectively). Drainage problems were not observed and it can therefore be stated that the Alcubillas vineyards are based on a ‘terroir’ term for the production of high quality grapes. In general, the soils are not subjected to treatments to control possible diseases or pests and we have therefore postulated that the soils represent the ideal scenario to establish a distinctive zone and for the increasingly valued ecological and natural viticultureThis research was funded by “Denominación de origen Valdepeñas” (denomination of origen), grant number UCTR18006

Agroecological analysis of cucumber (Cucumis sativus L.) crops in orchards in a Mediterranean environment

If adaptability is defined as the ability of a crop (or variety) to respond positively to changes in agricultural conditions, the purpose of this study was to explore the adaptability and relative influence of environmental factors on Cucumber Sativus L. to a specific Mediterranean environmental and agroecological site: Huete (Cuenca, Central Spain). Cucumber requires high temperatures and soil moisture for a satisfactory yield and maintaining an optimum level of humidity is very favorable, which is easy to achieve for farmers in Huete. Abundant sunshine is needed and this is another reason to cultivate during the summer period; it is estimated that there were between 2700 and 2800 hours of sunshine in the Huete area. The study described here revealed that the soils are poorly developed and evolved, with a simple Ap-C or Ap-Bw-C morphology. The soils are friable, slightly adherent and somewhat dry and hard. A significant feature is the presence of good drainage and appreciable effective depth. Like other crops, cucumber plants are preferably grown on loose, well-drained soils, such as the soils studied here. Huete cucumber seems able to tolerate certain levels of soil salinity when compared to other species. The cucumbers are irrigated with water with moderate electrical conductivity without an appreciable decrease in yield. Small doses of salinity may be one of the factors that leads to the characteristics associated with Huete cucumber, an aspect that would need to be investigated more deeply. Substrate nutrients and moisture management are two major concerns regarding Cucumber Sativus L. crops in Huete. Elemental chemical analysis revealed that strontium abounds and this is attributed to the presence of this element in the gypsums. The results of this study open a new horizon in the study of the aptitude of the land and represent a useful step towards the specific site and, consequently, the sustainable management of land under cucumber cultivation. Further research into a wider range of soils, fertilizer compositions and release rates is require

Black Truffle Production, Soils and Mediterranean Woods: Spanish Research Contributions (1962-2006)

The production of mycorrhizal fungi provides higher economic returns than any other forest product in many Mediterranean woods. In these areas, truffles (Tuber spp.) and mushrooms of Boletus and Lactarius genus are the fungi that yield the highest economic benefits. However, there are still evident gaps in the understanding of the truffle's biological cycles, ecology and interactions with host plants and other fungi. In the last 12 years, Spanish research has begun to respond to the requirements of truffle research. Most of Spanish Tuber references deal with the areas of agronomy, forestry, ecology and soil science. In this respect, Spain is one of the main truffle-producing countries in the world and its varied climate, topography and lithology make it a useful geographic area for increasing knowledge on Tuber ecology and truffle production. This work describes the content of Spanish research and its impact on the knowledge of truffles

Effect of Previous Crops and Soil Physicochemical Properties on the Population of Verticillium dahliae in the Iberian Peninsula

The soil infestation of Verticillium dahliae has significant Verticillium wilt of olive (VWO) with epidemiological consequences which could limit the expansion of the crop. In this context, there is a misunderstood history of the crops and soil property interactions associated with inoculum density (ID) increases in the soil. In this study, the effect of the combination of both factors was assessed on the ID of V. dahliae in the olive-growing areas of the Iberian Peninsula. Afterwards, the relationship of the ID to the mentioned factors was explored. The detection percentage and ID were higher in Spain than Portugal, even though the fields with a very favourable VWO history had a higher ID than that of the fields with a barely favourable history, regardless of the origin. The soil physicochemical parameters were able to detect the degree to which the ID was increased by the previous cropping history. By using a decision tree classifier, the percentage of clay was the best indicator for the V. dahliae ID regardless of the history of the crops. However, active limestone and the cation exchange capacity were only suitable ID indicators when <2 or 4 host crops of the pathogen were established in the field for five years, respectively. The V. dahliae ID was accurately predicted in this study for the orchard choices in the establishment of the olive