The inter-row soils in conventionally run citrus orchards in Eastern Spain lose fertility, either physically, chemically, or biologically, as a consequence of machinery traffic and the use of herbicides. In order to regain inter-row soil fertility, two grass-cover management alternatives to the commonly used herbicide-kept bare management, namely, spontaneous plants and fescue, were established and left for four years until their effects on several physical, chemical, and biological parameters were monitored for two years more. The fescue ground cover exhibited lower average and maximum soil temperatures due to higher evapotranspiration rates but also higher annual soil water content on average and, additionally, higher rhizodeposition. Despite the fact that these new beneficial conditions helped enhance the soil’s biological fertility under fescue, the physical or chemical fertilities did not improve and neither did the organic carbon (SOC). The spontaneous plants also enhanced the biological fertility, but in this case, beneficial conditions were reflected by improvements in the chemical fertility, particularly the exchangeable potassium, and in the physical fertility by increasing the surface hydraulic conductivity and decreasing the bulk density. In the inter-rows of this citrus orchard, a seeded grass cover does not seem able to provide any soil fertility enhancement in comparison to a spontaneous one; rather the opposite. However, a lack of natural or man-driven nitrogen inputs poses a constraint to SOC gains. For this aim, the annual surface application of organic nitrogen-rich materials or even better, the fostering of N-fixing organisms would be recommended.

Aim of the study: The nowadays avocado cropping world burst confronts water quality constraints as it unfolds throughout semi-arid climates. Therefore, many salt-tolerant rootstocks have been developed, with those from the West Indian avocado subspecies such as ‘Nachar’ standing out. However, the salt-tolerance of ‘Nachar’ had not been characterized and this study fills this knowledge gap. Area of study: Accordingly, an open-air trial was performed in Moncada (València). Material and methods: ‘Nachar’ seedling rootstocks grafted with ‘Hass’ avocado were irrigated with five nutritive solutions differing in chloride (Cl-), but with low sodium (Na+) adsorption ratio (SAR). Plant development and leaf nutrient status, including Cl- and Na+, were monitored, and the ‘Nachar’ salt-tolerance was characterized based on the accumulation rates of leaf Cl- and Na+ as a function of, respectively, Cl- and SAR in the irrigation water. These parameters are seldom expressly assessed but are argued here as providing better insight into the actual Cl- and Na+ exclusion ability of rootstocks than the usual maximum permissible, —to avoid leaf injury— leaf Cl- and Na+. Main results: The ‘Nachar’ was found to rank high and very high in, respectively, Cl- and Na+ exclusion ability, when compared to other avocado rootstocks. However, more salt-driven leaf injuries and potential yield losses would still be expected in avocado grafted onto the ‘Nachar’ in comparison to other salt-sensitive woody crops. Research highlights: The ‘Nachar’ seems an interesting starting point in further rootstock improvement for salt-tolerance in avocado. However, if unproperly carried out, the propagation of salt-tolerant avocado rootstocks such as ‘Nachar’ and others may also result in the loss of the previously achievements of salt-tolerance.