Effects of deficit irrigation and irrigation with saline drainage water on processing tomato (Lycopersicon esculentum Mill, cv. UC82B) yields, fruit quality, and fruit tissue constituents were investigated in two field experiments. Deficit irrigation reduced fruit water accumulation and fresh fruit yield, but increased fruit soluble solids levels and' led to higher concentrations of hexoses, citric acid, and potassium. Irrigation with saline water had no effect on total fresh fruit yield or hexose concentration, but slightly reduced fruit water content, which contributed to increased inorganic ion concentrations. Fruit set and marketable soluble solids (marketable red fruit yield × percent soluble solids) were generally unaffected by either irrigation practice. Water deficit and salinity increased starch concentration during early fruit development, but, at maturity, concentrations were reduced to < 1%, regardless of treatment. Higher fruit acid concentrations resulted from water deficit irrigation and from irrigation with saline water relative to the control in one year out of two. These results support the contention that deficit irrigation and irrigation with saline drainage water may be feasible crop water management options for producing high quality field-grown processing tomatoes without major yield reductions. Appropriate long-term strategies are needed to deal with the potential hazards of periodic increases in soil salinity associated with use of saline drainage water for irrigation.

Processing tomato (Lycopersicon esculentum Mill. cv. UC82B) plants were subjected to moderate levels of water deficit and salinity (Na2SO4/CaCl2) in sand culture. Fruit water content and the relative contributions of organic and inorganic constituents to fruit solute potential (Ψ) and soluble solids content were determined throughout development. Fruit Ψ averaged –0.63, –0.86 and –0.77 MPa in the control, salinity and water deficit plants, respectively. Reduced net water import and maintenance of solute accumulation, irrespective of water import, accounted for the reductions in Ψ of stressed fruits. Mineral ions (Na+, K+, Ca2+, Mg2+, Cl− and SO2‐4) contributed –0.31 MPa to Ψ in salinized fruit, compared with –0.19 MPa in control and water deficit treatments. Changes in net carbon accumulation were not observed among treatments, despite considerable differences in fruit K+ status. Starch accumulation in immature fruit was increased and hexose accumulation was decreased by both salinity and water deficit. Maximum starch levels were negatively correlated with total fruit Ψ, but were independent of fruit K+. Organic acid levels were generally higher throughout development in salinized plants, relative to control plants, and correlated with increased inorganic cation rather than anion accumulation in these fruits.

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Despite positive trajectories in global production during the last century, projected food demand and limits on our ability to further expand cropland now dictate an increase in food production by roughly 70% during the first half of the twenty-first century. Conventional systems of agriculture with their general emphasis on intensive soil disturbance, limited biodiversity, monoculture cropping and practices that mine the resource base are extractive and have resulted in slow yet demonstrably severe environmental degradation that ultimately jeopardizes food security for future generations. Because future gains in production are unlikely to be achieved by further increases in genetic yield potential, as have been achieved in the past, applications of new production system paradigms are going to be indispensable. Our existing ones are no longer able to compensate for, nor reverse, the environmental problems they have caused. We summarize the history of how agricultural systems have come to be what they are today and identify ways in which these systems will need to be improved to meet future food security challenges. We describe the development of food production system options that have been proposed in recent decades and show that the core principles and concepts of what are widely regarded as conservation agriculture (CA) systems provide an important unifying framework. Our chapter provides evidence for why these systems, when flexibly applied and in ways that mimic natural ecosystems, provide a best-bet approach for moving forward. We highlight a series of examples of CA systems being applied around the world and conclude by issuing a call to action aimed at developing and more widely adopting food production systems that look long-term, mimic natural systems and transcend jargon.