Effect of irrigation regimes and nitrogen rates on water use efficiency and nitrogen uptake in maize

Abstract

The nutritional responses to drying and rewetting cycles of partial root-zone irrigation still remains elusive. The effect of alternate partial root-zone irrigation (PRI) on water use efficiency and nitrogen (N) accumulation compared with deficit irrigation (DI) and full irrigation (FI) were investigated in maize (Zea mays L.) grown under three N-fertilization rates (1.5, 3.0, and 6.0 g N pot-1) and moderately and severely water-stressed levels (60 and 40% of soil water holding capacity). The plants were grown in split-root pots and exposed to FI, DI and PRI treatments from the fourth leaf to silking stage. Analysis across the N-fertilization treatments showed that both PRI and DI significantly decreased plant water use as well as plant height, girth, leaf area and shoot biomass, leading to similar WUE compared with the FI control. Carbon isotope composition (δ 13 C) was highest in PRI plants indicating a fine-tuned long-term stomatal control over gas exchange. Across the N-fertilization rates, FI plants accumulated significantly greater amount of N than deficit irrigation treatments. PRI and DI plants had similar plant δ 15 N, indicating the similar soil N mineralization. Plant dry biomass, which was linearly associated with plant N uptake, was similar for PRI and DI plants. Both resulted in the equivalent amount of N accumulation in the shoots of PRI and DI plants. It was noted that increased soil moisture level, e.g., from 40% to 60%, showed the tendency of increasing N uptake for PRI plants relative to DI plants. Therefore, in order to facilitate N uptake, the soil water availability in the wet soil compartment of PRI treatment should remain at high water levels.

Growth, production and water and nitrogen use efficiency of maize under water depths and nitrogen fertilization

“…These results are in agreement with Teixeira et al (2014), who found effect of water and nutritional stress on the reduction of LAI in irrigated maize, attributing these results especially to variations in the capacity to allocate resources, mainly in radiation and water use efficiency. According to Wang et al (2017), the increment in soil water availability increases N absorption, contributing to the linear increase of biomass in maize plants.…”

“…In most agricultural systems, crop yield is mainly limited by factors such as low nutrient and water availability, because they compromise physiological processes related to plant growth (Gonzalez-Dugo et al, 2010 ). The main nutrient required by the maize crop is nitrogen (N), because it is highly related to the reduction in plant production and to yield components (Teixeira et al, 2014;Wang et al, 2017). The large demand for inorganic N-based fertilizers often results in high application rates in the production process, thus requiring a rational management that considers the economic and environmental impacts of these practices (Djaman et al, 2013;Jia et al, 2014).…”

Yield determination of maize hybrids under limited irrigation

“…However, with climate change, severe and frequent droughts will greatly reduce soil water available for plant uptake (Rurinda et al 2015). In such conditions, the increasing shortage of freshwater will be the most limiting factor to maize productivity, particularly under arid or semi-arid climatic conditions (Wang et al 2017). Limited irrigation, with an amount less than the crop water requirement, has been recognized as a viable water-saving technique in preparation for future water-shortage scenarios.…”

Timely supplemental irrigation changed nitrogen use of wheat by regulating root vertical distribution

“…Because of the coupling of uptake of soil water and nutrients, it has been found that under low precipitation conditions, there is a reduction in N uptake by crops (Koutroubas et al, 2004;Wang et al, 2017). The total N uptake increased with increasing irrigation level, from 50 to 100% of field capacity (Hammad et al, 2016).…”

“…Approximately 70–80% of the current global water withdrawals are consumed for irrigating the agricultural land ( Lin et al, ; Wang et al, ). Increasing water shortages cause limited nitrogen use and limited increases in wheat yields, threatening future agricultural production ( Wang et al, ; ).…”