The sustainable utilization of saline resources for livestock feed production in arid and semi-arid regions: A model from Pakistan

Abstract

Degraded land area is increasing in many arid and semi arid countries (UNEP, 2010). Additionally, fresh water resources are becoming limited and routine irrigation practices in conventional agriculture are causing a steady increase in soil salinity. This will lead to further desertification of affected areas in the future with concomitant reduction in the yield of crops known for human and animal consumption. Consequently it has become imperative to search for suitable alternatives and develop ecologically sustainable and economically sound biological systems that can use low quality water and drought affected saline lands to produce plants of economic importance. A large number of halophytes could be used as animal forage/fodder without encroaching upon arable lands and irrigation water. This paper emphasizes the agricultural importance of these salt tolerant plants in a world where most of the water is saline at any given moment. However, the economic use should be in accordance with the ecological demands suited to particular biomes. Pakistan for example, is spread over an area of 800,000 square kilometers with varied climatic conditions ranging from temperate to sub-tropical desert, eventually displaying a high biodiversity in local flora including halophytes. About 16% of the world halophytic flora is distributed in Pakistan with more than 410 species and among them >100 have potential economic usages as cattle feed. A number of these species are also distributed in the regions between the Atlantic coasts of Africa to western India. The Sindh/Balochistan coast of Pakistan extending from Seer Creek to Jiwani and from coast to mountains including Indus basin are rich sanctuaries for many of these plants. There is a need to conduct systematic survey of this flora, ascertain their chemical characteristics for nutritive value and subsequently identify the species suited to particular conditions through animal feeding trials. Some of these trials have already indicated a promise for ecologically sustainable use of perennial grasses such as Panicum antidotale, formerly identified as Panicum turgidum and Desmostachya bipinnata that may be taken to commercial scale. The system that was developed in Pakistan may serve as a model to other semi-arid subtropical countries of the region.

Salt-Tolerant Halophyte Rhizosphere Bacteria Stimulate Growth of Alfalfa in Salty Soil

“…In many of these areas, soil salinity has been increasing due to drought combined with poor irrigation practices. Most crop plants are sensitive to salt, which leads to reductions in production (reviewed in Gul et al, 2014). The severity of increasing soil salinity will likely intensify with growing food demand and degradation and loss of prime agricultural land.…”

“…Salinity increases in irrigated areas due to soluble salts carried in the irrigation water that remain in the soil after evaporation and transpiration. Unless these salts are leached from the soil, they accumulate to levels that are inhibitory to plant growth and may lead to soils becoming sodic, causing degradation of soil structure to affect water and root penetration along with other problems (Gul et al, 2014). According to USDA estimates, about 10 million hectares are lost globally each year as a result of salinity and/or waterlogging.…”

“…Over the past few decades, considerable progress has been made in understanding physiological mechanisms and gene expression changes involved in salt tolerance in halophytes (Shabala, 2013; Diray-Arce et al, 2015). Some halophytes have been developed or have potential for use as crop plants (Khan et al, 2009; Gul et al, 2014). However, little is known about the potential contribution of microorganisms associated with these plants in the soil, on plant surfaces, or within plant tissues.…”

Potential of Halophytes as Cattle Fodder: A Case-Study in Pakistan

“…This is especially true in long term use like feeding cows kept for milk. Before recommending such a practice, there is a need to conduct extensive feeding trials to formulate a suitable combination of halophytes and traditional non halophytes, which when fed to animals would have no/minimum ill effects on their health and simultaneously produce good quality meat/milk (Gul et al, 2014). In the present study, the use of halophytic resources has been explored in feed of animals raised for meat.…”

Biomining Sesuvium portulacastrum for halotolerant PGPR and endophytes for promotion of salt tolerance in Vigna mungo L.

“…Unless these salts are leached from the soil, they accumulate to levels that are inhibitory to plant growth and may lead to soil salinity. In the long run, salinity causes the degradation of soil structure affecting water and root penetration along with other problems ( Gul et al, 2014 ). In these cases, phytoremediation comes as a viable alternative to ensure soil productivity, preferably halophytes that have evolved to grow in saline soils and uptake salt ( Flowers and Colmer, 2015 ).…”