Developing Cropping Sequence Options for Salt-Affected Rice-Based Production Systems in the Nile Delta and Iran

Research Article

Austin J Plant Biol. 2015; 1(2): 1009.

Developing Cropping Sequence Options for Salt-Affected Rice-Based Production Systems in the Nile Delta and Iran

Dakheel AJ, Hussain IM* and Shabbir G

Department of Crop Diversification and Genetic Improvement Section, International Center for Biosaline Agriculture (ICBA), UAE

*Corresponding author: M Iftikhar Hussain, Department of Crop Diversification and Genetic Improvement Section, International Center for Biosaline Agriculture (ICBA), P.O. Box 14660, Dubai, UAE

Received: July 12, 2015; Accepted: December 08, 2015; Published: December 14, 2015

Abstract

The cropping cycles of the rice production systems take place from May to September in the Nile Valley and the Caspian Sea region of Iran. Farmers plant several traditional crops to fill the gap between two cycles to maximize productivity. However, in salt-affected areas crop selection and management must be adjusted to maintain favorable farm income levels. Two types of crops: A-fast-growing forages that can be planted in September and harvested in late November before the winter crops are sown and B-salt-tolerant crops that fit the whole period between two cycles are needed. Over the past few years, several production systems that fit these criteria have been evaluated at ICBA and at several national research system sites in the region. A large number of genotypes of fast-growing, salt-tolerant forages like barley, pearl millet, sorghum, fodder beet and forage brassica were evaluated at salinity levels up to 15 dS/m under field conditions. Nurseries of forage crops containing 25-30 genotypes/varieties with high yield potential under saline conditions were assembled and distributed to several national programs along with appropriate management packages. Similarly, ICBA developed nurseries of oilseed crops like safflower and canola to distribute to the selected farmers. ICBA also developed appropriate production and management packages that incorporate crop selection, irrigation and soil management and crop management practices for optimum production in salt-affected environments. These genotypes showed excellent tolerance to medium and highly salinity levels. Yield was decreased only by 12-15% at medium salinity (10 dS/m) and about 30% at high salinity (15 dS/m) level. Yield of brassica ranged from 16.8 to 29.8 T/ha, fodder beet above ground yield from 2.95 to 4.26 t/ha, fodder beet tuber yield from 7.14 to 12.08 t/ha and barley yield ranged from 7.6 to 10.6 t/ha at 5 ds/m and 15 dS/m respectively. The dry matter production of single cut and multi cut sorghum genotypes ranged between 11.1 and 31.9 and 5.4 to 7.9 t/ha respectively. The dry matter production of single cut and multi cut pearl millet genotypes ranged between 7.1 to 30.7 t/ha and 21.8 to 31.7 t/ha respectively. Continuous use of medium and high salinity water increased the soil salinity in the root zone (0-30 cm).

Keywords: Salt-affected rice systems; Short duration forages; Rice crop rotation; Forage production packages; Genotypes; Salt tolerant and salinity; Biomass

Introduction

Soil and irrigation water salinity has emerged as a stress and limiting factor to crop production especially in salt affected areas. Soil salinity is being progressively increased by irrigation and fertilization, especially in the arid and semi arid regions. Salts inhibit plant growth by osmotic stress, nutritional imbalance, and specific ion toxicity [1- 4]. It is estimated that more than 50 per cent of the irrigated lands in arid and semi-arid regions of the world are affected to some degree from salinization. About 21% of the world irrigated area was affected from soil salinity (Table 1). Millions of hectares of agricultural land have been abandoned because of salinity hazards. Besides, there are large areas, which are potentially vulnerable and could easily be damaged by salinization through irrigation. Rice (Oryza sativa) is the staple food for nearly half of the world’s population and a key source of employment and income for the rural people especially in developing countries. The crop occupies one third of the world’s total area planted by cereals. It is the most widely grown crop under irrigation. In 2002, 2.6% of the rice harvested area was located in the Near East Region. It is one of the major field crops in Egypt and occupies about 0.65 million hectares, produces approximately 6 million metric tons of rough rice annually and contributes about 20% to the per capita cereal consumption. The country has several production zones and ranks as one of the highest in the world in terms of productivity per unit area. It is also the second main crop consumed in Iran, after wheat. The production of paddy rice in Iran is currently around 2,000,000 tons from a cropped area of 533,000 hectares, all of which is irrigated. Barley is an important and one of the most salt-tolerant crop species among the glycophytes [5]. It is cultivated over a large area irrigated lands in the world. It has several, important economic and social benefits. It provides food for humans, feed for animals and poultry and raw material for malt industry. Canola can produce 1.0 to 2.0 tons of dry matter per acre in a single season.