Under semi-arid regions in mediterranean ecosystems we are appliying with nice results the mycorrhizal fungus application, a natural and sustainable method. Mycorrhizal fungus change the properties of soil and benefit the water retention. Furthermore the have acces to smaller pores and capilary water that is inaccessible for roots and explore much larger areas. Also influence the hydraulic lift not only between deep and upper soil layers but also between plants conected by the same fungal community. Even more, mycorrhiza symbiosis can change the strategy of the plants to cope with changing condicions giving to the plant flexibility between apoplastic and cell to cell pathways and improving the antioxidant and osmoregulation systems, allowing the plant to continue the vegetative growth under water deficit stress conditions.

Water scarcity is one of the major constraints for agricultural development in arid and semiarid areas. It is imperative to identify and implement technologically feasible, socially, economically and environmentally acceptable irrigation water and crop management practices for optimum agricultural production and productivity under drought and deficit water supply conditions. Within the context, the water management "how much water at what time" is influencing due to the deference in water requirement of the crop under different growth stages. Applying water only in the growth stage sensitive for water stress is one way of managing the scarcely available water. This can be achieved by more careful consideration of the timing, frequencies, amounts and application methods of water. Other practices include increasing water use efficiency (WUE), precision irrigation systems like drip irrigation, preventing water losses due to runoff, deep drainage or evaporation from the soil surface and application soil additives with better water holding capacity.

True Yogesh. In Middle east amist severe aridity agricultural production is not bad for one reason, resources put are too much. Most of the bigger farms have Center pivot with sprinkler irrigation and teh sprinklers are changes regularly depending on the growth stage and the cropwater requirements. Similar strategy can be adopted in India and other developing countries, but the bigger issue will be of dependable energy to run this system and the other will be of the size of landholdings. Such mechanized agriculture is possible if we develop a system of cooperative and shares for farmers and merge these smaller farms into a agriculture industry which is owned collectively by these farmers. There are no cheaper solutions to these bigger issues and there should be some innovative thinking in combating the issues.

hello sir... im just an fresher/beginner... in my observation in the Organic fields ( in my study areas)... they prefer drip irrigation + mulching/ground cover (precisely) to maintain the moisture or to increase/retain water availability in the soil) as it reduces the water loss due to evoptrn.

Consider biochar.

I acknowledge that lignocellulosic biomass is required to make biochar and this may not be freely available in arid regions.

For general information, see http://www.biochar-international.org/biochar

For an example about moisture-retention, see http://onlinelibrary.wiley.com/doi/10.1111/sum.12102/pdf .That applies to Denmark, but the problem of moisture-retention is the same.

In natural semi-arid ecosystem, shrubs that are able to do hydraulic redistribution can increase water in upper soil layers (during dry conditions) but also increase the water in deep soil layers (during the rainy periods), through their root systems. See Prieto et al. (2010). Hydraulic lift through transpiration suppression in shrubs from two arid ecosystems: patterns and control mechanisms. Oecologia 163: 855-865.

Under arid and semi-arid conditions, one can consider using polyacrylamide (PAM), which not only increases the amount of available water and WUE, but also prevents soil erosion and crop damage due to sand and dust storms. PAM can be introduced to the soil as a powder or suspension.

Under semi-arid regions in mediterranean ecosystems we are appliying with nice results the mycorrhizal fungus application, a natural and sustainable method. Mycorrhizal fungus change the properties of soil and benefit the water retention. Furthermore the have acces to smaller pores and capilary water that is inaccessible for roots and explore much larger areas. Also influence the hydraulic lift not only between deep and upper soil layers but also between plants conected by the same fungal community. Even more, mycorrhiza symbiosis can change the strategy of the plants to cope with changing condicions giving to the plant flexibility between apoplastic and cell to cell pathways and improving the antioxidant and osmoregulation systems, allowing the plant to continue the vegetative growth under water deficit stress conditions.