Enhanced Plant Rooting and Crop System Management for Improved N Use Efficiency

Abstract

Despite the significant inroads into increasing agricultural productivity in recent decades, nitrogen remains a key limiting factor for crop growth and yield. Though highly variable globally, the amount of reactive N added yearly onto cropland that is subsequently lost to the environment remains high. As such the interest in agronomic approaches to address this and improve nitrogen use efficiency (NUE) is currently very high. Here, we have shown the combined approaches of management interventions such as no-till, intercropping with leguminous and grass species, use of nitrogen inhibitors, and combined crop-livestock systems offer considerable potential for enhancing NUE and are already being readily deployed in the tropics. Grass species such as Brachiaria in particular have demonstrated enormous potential via their deep root architectures to reduce losses by leaching. However, the potential for increases in NUE through interaction and association of the root systems with the soil microbial community via rhizodeposits remains a major area for future research. Increasingly it is recognized that truly enhancing NUE requires consideration of the whole system. Improving

Maize-Brachiaria intercropping: A strategy to supply recycled N to maize and reduce soil N2O emissions?

“…Moreover, this study highlights that there was no negative effect of the intercropping system on maize grain yield, supporting the benefit of the interaction of two plant species growing at the same time and space ( Ehrmann and Ritz, 2013 , Rosolem et al, 2017 ).…”

Nitrogen-Fertilized Systems of Maize Intercropped With Tropical Grasses for Enhanced Yields and Estimated Land Use and Meat Production

“…The N fertilizer rate of 100 kg ha −1 was considered relatively low for complex intercropping systems, but was compatible with our study's focus on finding an efficient N management strategy for enhancing productivity in a sustainable manner. Indeed, we observed greater maize yield and forage dry matter production compared to other studies with application rates of <100 kg N ha −1 (Mateus et al, 2016;Rosolem et al, 2017).…”

Use of nutrient-enriched zeolite (NEZ) from urban wastewaters in amended soils: Evaluation of plant availability of mineral elements

“…This study reveals that the C/N ratio for both clay and sandy soils was > 45, but higher C/N ratio values were reported by Rosolem et al (2017), which seems to be related to the higher uptake of nitrogen by plants (Rosolem et al, 2017). However, other works also reported that C/N ratios < 30 are optimal for a good nitrogen mineralisation, so nitrogen is released for plant uptake, but C/N ratios > 30 revealed that nitrogen was immobilised and not available for plants (Brust, 2019).…”