oa Improving Water and Nutrient Use Efficiency for Crop Production in Dry Lands via Soil Amendments and Remote Sensing Techniques

The soils of the Arabian Peninsula in general and GCC countries in specific are dominantly sandy (low nutrient and water holding capacity, high infiltration rate). These soils need high inputs for crop production. To be cost-effective in agriculture production these soils need careful consideration to enhance water and nutrient use efficiency and increase crop production. A number of organic and inorganic amendments have been used by various researchers in this regards. However, little has been done in this respect on UAE soils, and hence forms the focus of this study. The study aims to achieve this through soil improvement using soil amendments and assessing the efficiency through remote sensing techniques.

The green house and field trials were conducted simultaneously (January 2015) on Okra (Abelmoschus esculentus) at ICBA station using sandy soil which is dominant in the UAE and the GCC countries. Five inorganic amendments (Zeoplant, Zeoplant pellet, Meliorit, AustaHort and Palagonite) and one organic (locally produced compost) were used at different rates (0, 1.5, 3 and 4.5 kg/m²). Fresh water is used to offset the irrigation requirement of Okra equivalent to 100% and 75% ETc. The treatments were triplicated in a randomized complete block design.

Agronomic parameters (Germination, growth, flowering and fruiting) were recorded. Spectral signatures were collected in the range of 400 to 1100 nm using a hand held spectroradiometer with standardized viewing and radiation conditions for all treatments. Each parcel was monitored spectrally from the stage of being a bare parcel to the stage of 50% covered by vegetation.

Okra fruit is collected on a weekly basis and weight recorded. The SPAD meter is used in the field and greenhouse for the measurement of chlorophyll content during the growth stages.

The organic and inorganic amendments in general improved the water use efficiency as well as enhanced the biomass production to a significant extent compared to the treatment where amendments were not used. At 75% ETc the performance of amended soils was comparable to 100% ETc and fruit biomass production was similar. The use of the soil amendments can save up to 25% of the irrigation water in sandy soils.

These are preliminary results from sandy soil representing the main soil type in UAE. These amendments may behave differently in other types of soils hence further test are being started in Arabian Gulf University to test the same amendments on Bahraini soil.

Keywords

Water scarcity, Crop production, Sandy soils, Water and Nutrient Use Efficiency, Monitoring efficiency, UAE