Simultaneous Assessment of Water and Nitrogen Use Efficiency in Rain-Fed Chickpea-Durum Wheat Intercropping Systems

Abstract

It is well known that multiple interactions can occur between nitrogen and water use, depending on climate, soil and crop characteristics, in crop growth and yield development. However, little is known about the simultaneous change in both water and N use efficiency (WUE and NUE) and their possible interactions in cereal–-legume intercropping systems. In order to advance our knowledge on the N and water facilitation mechanisms involved in the intercropping responses of N and water input co-limitations, we investigated, via four experiment years, the simultaneous optimization of water and N-fertilizer inputs, as well as its possible effects on growth, yield, N acquisition, and the NUE and WUE in intercropped species. The results indicated that intercropping increases the leaf area index by more than +0.14 and +1.03 units when compared to durum wheat and chickpea monoculture systems, respectively. This increase is particularly noticeable under higher rainfalls during the crop period (i.e., as can be seen in the 2022, 2020, and 2019 seasons). Moderate N-application enhanced both the grain yield and protein accumulation in the mixed crops by more than 0.22 t ha−1 and 57 kg ha−1, respectively. Conversely, intercropping significantly decreased the mixed grain yield when compared to durum wheat monocultures. Intercropping advantages in terms of biomass (ranged from 1 to 44%) and N-acquisition (2 to 91%) was confirmed in either low- (2021) or high- (2019 and 2022) rainfall growing periods, but only under low and moderate N-applications. Improving N nutrition under both rainfall and drought growth periods was confirmed only for the mixed crops under all applied N-fertilizer doses. Such improvements in growth, N acquisition, and yield quality were most likely achieved by positive interactions (r2 = 0.73, p ≤ 0.001) between the NUE and WUE for the chickpea–wheat intercropping. Thus, 0.62 kg m−3 of WUE promotes a significant increase of 1 kg kg−1 in NUE by mixing chickpea-durum wheat. Rain-fed chickpea-durum wheat intercropping provides a higher performance in growth and yield quality compared to sole cropping systems; this may occur from the simultaneous optimizations of both water and N fertilizer inputs in low-N soil under semiarid conditions.

The simultaneous assessment of nitrogen and water use efficiency by intercropped pea and barley under contrasted pedoclimatic conditions

“…Indeed, the higher precipitation during the January-April period would allow for better vegetative growth of the crops, resulting in higher yields. Similar findings have been reported by Kherif et al (2023) for sole crops and intercropping of chickpea and wheat, attributing higher yields to a better distribution of precipitation throughout the growing season. The variation in rainfall distribution could also explain the extremely low LAI values in site 3, where a severe drought period was reported during the vegetative growth phase despite relatively high total precipitation for the 2022 season.…”

“…Regarding NUE and WUE during the 2021 seasons, we found that both NUE and WUE were generally higher for sole cropped barley, followed by the mixed crop. These results are in line with previous studies on cereal-legumes intercropping (Kherif et al 2023). The only exception was the NUE in site 3, where the sole cropped pea had the highest NUE value.…”

“…Ultimately, this could lead to a simultaneous optimization of water and N use, particularly in the context of low-input agriculture (El-Madany et al 2021). Kherif et al (2023) conducted a four-year field experiment on intercropping cereals and grain legumes for human food production in the semi-arid region of Algeria, simultaneously assessing WUE and NUE. This study reported a positive interaction between WUE and NUE in the durum wheat-chickpea intercropping system, demonstrating higher growth performance and improved grain protein content compared to monoculture.…”

“…It´s important to note that the N status at both the soil and crop levels is closely connected to water availability. Recent research studies have highlighted that in both monoculture and intercropping systems, water restrictions induce a substantial decrease in NUE when nitrogen inputs are not optimally available compared to crop demand (Quernada et al 2016;Kherif et al 2023) In the semi-arid regions of Algeria, the dominant agricultural practice is durum wheatfallow rotation (Latati et al 2014). However, the Algerian farming community is increasingly exploring the adoption of intercropping systems involving cereals and legumes as an alternative solution to improve land use, profitability, and sustainability on their farms (Latati et al 2019).…”

Impact of Cereal–Legume Intercropping on Changes in Soil Nutrients Contents under Semi–Arid Conditions

“…This agricultural practice is grounded in ecological principles, specifically facilitation and complementarity [6,8]. Furthermore, intercropping systems combining legumes and cereals are widely acknowledged as highly efficient cropping systems with the potential to optimize the utilization of resources, particularly nitrogen and water [10,11]. Moreover, these systems have demonstrated increased resilience to abiotic stressors, such as drought, and offer effective strategies for weed, pest, and disease management without relying on herbicides [12][13][14].…”