Effects of Biochar on Irrigation Management and Water Use Efficiency for Three Different Crops in a Desert Sandy Soil

Giorgio Baiamonte,Mario Minacapilli,Giuseppina Crescimanno

doi:10.3390/su12187678

Giorgio Baiamonte, Mario Minacapilli + Show 1 more

Open Access

https://doi.org/10.3390/su12187678

Copy DOI

Journal: Sustainability	Publication Date: Sep 17, 2020
Citations: 10	License type: CC BY 4.0

Affiliation: University of Palermo

Abstract

This paper aimed at investigating if the application of biochar (BC) to desert sand (DS) from the United Arab Emirates (UAE), characterized by a very poor soil-water retention (SWR) and by a very low value of the maximum water available for crops (AWmax), could positively affect soil water balance, by reducing the irrigation needs (VIRR) and improving the irrigation water use efficiency (IWUE) and the water use efficiency (WUE). The analysis was performed for three crops, i.e., wheat (Triticum aestivum), sorghum (Sorghum vulgare) and tomato (Lycopersicon esculentum). BC was applied to the DS at different fractions, fBC (fBC = 0, 0.091, 0.23 and 0.33). Drip irrigation was adopted as a highly efficient water saving method, which is particularly relevant in arid, water-scarce countries. Soil water balance and irrigation scheduling were simulated by application of the AQUACROP model, using as input the SWR measured without and with BC addition. The effect of BC was investigated under either a no-water stress (NWS) condition for the crops or deficit irrigation (DI). The results showed that the application of BC made it possible to reduce the predicted VIRR and to increase the IWUE under the NWS scenario, especially for wheat and sorghum, with less evident benefits for tomato. When a deficit irrigation (DI) was considered, even at the lowest considered fBC (0.091), BC counterbalanced the lower VIRR provided under DI, thus mitigating the yield reduction due to water stress, and improved the WUE. The influence of BC was more pronounced in wheat and tomato than in sorghum. The results evidenced that the application of BC could be a potential strategy for saving irrigation water and/or reducing the effects of drought stress in desert sand. This means that biochar could be used a management option to promote local production and reduce the dependency on food import, not only in the UAE, but also in other countries with extremely arid climatic conditions and large extensions of sandy soils similar to the considered DS.

Highlights

Fresh water is an indispensable natural resource, which plays a vital role in the development of any country
Since AWmax increased at increased fBC, indicating a greater ability of the soil to store water as a consequence of BC addition, this explains why lower VIRR values were predicted when BC was applied at higher fBC and application depths (ZDS+BC)
This investigation showed that the application of biochar to a desert sand for three crops, i.e., wheat, sorghum and tomato, positively affected the soil water balance and the irrigation scheduling simulated by the AQUACROP model, using as input accurately measured soil hydraulic parameters representing the physical and structural condition of the soil without and with BC addition

Summary

Introduction

Fresh water is an indispensable natural resource, which plays a vital role in the development of any country. The world could face a 40% global water deficit by 2030 under a business-as-usual scenario [3]. Water withdrawal for agricultural purposes accounts for about 75% of all usages in developing countries, and irrigation is widely criticized as a wasteful user of water, especially in the water-scarce regions [4]. Under these critical water availability conditions, a rational management of water is essential to enhance water productivity, i.e., the ratio between the agricultural benefit and the water supplied [5]

Objectives

Methods

Results

Conclusion