Interrelation between harvester ant activity, soil fertility, and land management in the arid lands of the Negev Desert, Israel

Much of the open lands in arid areas are highly degraded reaching a state grazing or crop yields become low and non-profitable a state grazing or crop yields become low and non-profitable. Implementation of deep tilling and fertilization to enhance yields may cause destructive outcomes for the environment. An alternative approach may be conservation agriculture practices also involving the triangular interrelation among the harvester ant activity, soil fertility, and land management practices to maximize and increase the sustainable agricultural utilization of semi-arid farm land. In order to define this interrelation, a study was carried out at three sites in the northern Negev, Israel between 2014 and 2017. In each site, three different land management practices were carried out (cereal breeding, grazing, and conservation). The findings indicate that in the first three years, the harvester ants' foraging activity increased soil organic matter content by 0.25% per year, followed by an increase of 0.5 % year⁻¹, caused by ants' nesting and foraging. In this state, partial grazing or rainfed crop breeding using a conservative tillage scheme can be carried out until sustainability. Cultivations such as fertilizing with organic matter and land management practices such as savanna trees or local perennials plantations may strengthen the interrelation among the harvester ant activity, soil fertility and biological productivity leading to an increased sustainable agriculture utilization.