Rising sea levels and salinization of groundwater due to global climate change result in fast-dwindling sources of freshwater. Therefore, it is important to find alternatives to grow food crops and vegetables. Halophytes are naturally evolved salt-tolerant plants that are adapted to grow in environments that inhibit the growth of most glycophytic crop plants substantially. Members of the Salicornioideae are promising candidates for saline agriculture due to their high tolerance to salinity. Our aim was to develop genetically characterized lines of Salicornia and Sarcocornia for further breeding and to determine optimal cultivation conditions. To obtain a large and diverse genetic pool, seeds were collected from different countries and ecological conditions. The external transcribed spacer (ETS) sequence of 62 Salicornia and Sarcocornia accessions was analysed: ETS sequence data showed a clear distinction between the two genera and between different Salicornia taxa. However, in some cases the ETS was not sufficiently variable to resolve morphologically distinct species. For the determination of optimal cultivation conditions, experiments on germination, seedling establishment and growth to a harvestable size were performed using different accessions of Salicornia spp. Experiments revealed that the percentage germination was greatest at lower salinities and with temperatures of 20/10 °C (day/night). Salicornia spp. produced more harvestable biomass in hydroponic culture than in sand culture, but the nutrient concentration requires optimization as hydroponically grown plants showed symptoms of stress. Salicornia ramosissima produced more harvestable biomass than Salicornia dolichostachya in artificial sea water containing 257 mM NaCl. Based on preliminary tests on ease of cultivation, gain in biomass, morphology and taste, S. dolichostachya was investigated in more detail, and the optimal salinity for seedling establishment was found to be 100 mM. Harvesting of S. dolichostachya twice in a growing season was successful, but the interval between the harvests needs to be optimized to maximize biomass production.

Bioirrigation has been defined as the transfer of hydraulically lifted water by a deep-rooted plant to a neighbouring shallow-rooted plant which cannot access deep soil moisture. In this study, we tested if facilitative effects of bioirrigation or the competition for water dominate the interaction of two intercropped plants—deep-rooted pigeon pea (PP) and shallow-rooted finger millet (FM) before and during a drought. Additionally, we tested how the presence of a common mycorrhizal network (CMN) affects the balance between facilitative (i.e. bioirrigation) and competitive interactions between two intercropping species. Our results show that PP can indeed promote the water relations of FM during a drought event. Specifically, stomatal conductance in FM controls dropped to low values of 27.1 to 33.6 mmol m^-2s^-1, while FM in intercropping treatments were able to maintain its stomatal conductance at 60 mmol m^-2s^-1. In addition, the presence of PP reduced the drought-induced foliar damage and mortality of FM. The observed facilitative effects of PP on FM were partially enhanced by the presence of a CMN. In contrast to the facilitative effects under drought, PP exerted strong competitive effects on FM before the onset of drought. This hindered growth and biomass production of FM when intercropped with PP, an effect that was even enhanced in the presence of a CMN. The results from our study thus indicate that in intercropping, deep-rooted plants may act as "bioirrigators" for shallow-rooted crops and that a CMN can promote these facilitative effects. However, the interspecific competition between the intercropped plants under conditions of abundant moisture supply can be strong and are enhanced by the presence of a CMN. In more general terms, our study shows that the extent by which the antagonistic effects of facilitation and competition are expressed in an intercropping system strongly depends on the availability of resources, which in the case of the present study was water and the presence of biotic interactions (i.e. the presence of a CMN).

Core Ideas: Strip‐seeding of clovers into bermudagrass swards resulted in similar clover stand percentage compared with solid planting of clovers. Heifers grazing pastures that were strip seeded performed similarly to heifers grazing clovers that were seeded in solid stands. Red clovers persisted longer into the summer than either white or subterranean clovers. Red clover provided greater animal performance than white and subterranean clovers. Even though clovers can provide improved forage quality and reduced N fertilization when grazing stocker calves on warm‐season grass pastures, stand establishment remains a concern. The objective of this research was to determine if alternative methods of seeding legumes into warm‐season perennial swards could improve legume establishment. This research took place on 18, four‐acre mixed bermudagrass [Cynodon dactylon(L.) Pers.], crabgrass [Digitaria ciliaris(Retz.) Koeler], and dallisgrass (Paspalum dilatatumPoir.) pastures at the University of Arkansas Southwest Research and Extension Center Stocker Unit. Pastures were seeded in October of 2013 to white (Trifolium repensL.), red (Trifolium pratenseL.), or subterranean (Trifolium subterraneumL.) clovers either in solid stands at the recommended rate (2.0, 8.0, and 11 lb/acre, respectively) or in four 0.25‐acre strips at twice the recommended seeding rate in a 3 × 2 factorial arrangement of treatments with three pasture replications per treatment combination. Growing heifers (n= 216; 614 ± 44.4 lb) grazed pastures from May to September 2014 and April to September 2015. Red clover was present later into the summer than white or subterranean clovers, but there were no differences due to seeding method. At the end of the grazing season, heifer bodyweight and gain was greater when grazing red clover than when grazing subterranean clover. Strip‐seeded clovers in only 50% of the pasture area provided similar stands to conventional solid seeding and equivalent animal performance. Red clover grew later into the summer grazing season and provided greater animal performance than white and subterranean clovers.

Biofertilization via the inoculation with arbuscular mycorrhizal fungi (AMF), combined with rhizobia and plant growth promoting rhizobacteria (PGPR), are beginning to become established as an effective and sustainable measure to improve yields. Biofertilization might have a particular potential to boost the yield of intercropping systems in rainfed areas because AMF can form a common mycorrhizal network (CMN) that can transfer nutrients and water between two plants and balance as such belowground competition. In this study, we tested if biofertilizers can enhance the yield of intercropping systems using a pigeon pea (PP) – finger millet (FM) intercropping system grown for two consecutive growing seasons (2016/17 and 2017/18) at two contrasting sites in Bengaluru and Kolli Hills, India. To validate the process of bioirrigation (transfer of water between rhizosphere of two plants), we tested, for the first time, if the spatial arrangement of intercropped plants using either a row-wise or a mosaic design affected yield and water relations with and without biofertilizers. Our results demonstrate that intercropping can improve the straw and grain yield in PP–FM intercropping compared to the respective monocultures but that intercropping effects vary depending on the site characteristic such as climate and soil type. Spatial arrangement of component plants affected the total, straw and grain biomass in intercropping treatments, but this effect also varied across sites. Most importantly, the results from the 2017-18 growing season clearly demonstrated a positive effect of biofertilizer on biomass yield, and this effect was irrespective of site, spatial arrangement, mixed or monoculture. Despite a yield increase in intercropping, we did not see a positive effect of biofertilization on water relations of FM possibly due to interspecific competition for soil moisture where PP dominated. In summary, our study shows the potential of biofertilizers to increase the yield of intercropping systems in rainfed dryland agriculture.