Soil nitrogen dynamics after Brachiaria desiccation

Castoldi, Gustavo; Reis, Jhônatas Gomes dos; Pivetta, Laércio Augusto; Rosolem, Ciro Antônio

doi:10.1590/s0100-06832013000600018

Cited by 12 publications

(9 citation statements)

References 30 publications

(37 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, our results confirmed that during the early stage after establishment of the Bh genotypes, there was no significant influence of BNI on microbial nitrification. This observation is consistent with other studies on BNI expression with young Bh plants ( Miranda et al, 1994 ; Castoldi et al, 2013 ; O’Sullivan et al, 2016 ). Therefore, it is suggested that applied urea N (hydrolyzed to

within a few days) during transplanting had a strong stimulation effect on growth and activity of soil nitrifiers, and that the microbial formed

was leached rapidly in the first rainy season when the grass was still small.…”

Section: Discussionsupporting

confidence: 94%

Low 15N Natural Abundance in Shoot Tissue of Brachiaria humidicola Is an Indicator of Reduced N Losses Due to Biological Nitrification Inhibition (BNI)

et al. 2018

View full text Add to dashboard Cite

The tropical forage grass Brachiaria humidicola (Bh) suppresses the activity of soil nitrifiers through biological nitrification inhibition (BNI). As a result, nitrate (NO3−) formation and leaching are reduced which is also expected to tighten the soil nitrogen (N) cycle. However, the beneficial relationship between reduced NO3− losses and enhanced N uptake due to BNI has not been experimentally demonstrated yet. Nitrification discriminates against the 15N isotope and leads to 15N depleted NO3−, but 15N enriched NH4+ in soils. Leaching of 15N depleted NO3− enriches the residual N pool in the soil with 15N. We hypothesized that altered nitrification and NO3− leaching due to diverging BNI magnitudes in contrasting Bh genotypes influence soil 15N natural abundance (δ15N), which in turn is reflected in distinct δ15N in Bh shoot biomass. Consequently, high BNI was expected to be reflected in low plant δ15N of Bh. It was our objective to investigate under controlled conditions the link between shoot value of δ15N in several Bh genotypes and leached NO3− amounts and shoot N uptake. Additionally, plant 15N and N% was monitored among a wide range of Bh genotypes with contrasting BNI potentials in field plots for 3 years. We measured leaf δ15N of young leaves (regrown after cutback) of Bh and combined it with nitrification rates (NRs) of incubated soil to test whether there is a direct relationship between plant δ15N and BNI. Increased leached NO3− was positively correlated with higher δ15N in Bh, whereas the correlation between shoot N uptake and shoot δ15N was inverse. Field cultivation of a wide range of Bh genotypes over 3 years decreased NRs in incubated soil, while shoot δ15N declined and shoot N% increased over time. Leaf δ15N of Bh genotypes correlated positively with NRs of incubated soil. It was concluded that decreasing plant δ15N of Bh genotypes over time reflects the long-term effect of BNI as linked to lower NO3− formation and reduced NO3− leaching. Accordingly, a low δ15N in Bh shoot tissue verified its potential as indicator of high BNI activity of Bh genotypes.

show abstract

within a few days) during transplanting had a strong stimulation effect on growth and activity of soil nitrifiers, and that the microbial formed

was leached rapidly in the first rainy season when the grass was still small.…”

Section: Discussionsupporting

confidence: 94%

Low 15N Natural Abundance in Shoot Tissue of Brachiaria humidicola Is an Indicator of Reduced N Losses Due to Biological Nitrification Inhibition (BNI)

et al. 2018

View full text Add to dashboard Cite

show abstract

“…In fact, these results confirm the observation made by Castoldi et al (2013), In fact, these results confirm the observation made by Castoldi et al (2013), where only the variances observed on the NH4+ and NO3-contents on the soil were not enough to confirm the nitrification suppressor effect of the B. humidicola, B. brizantha, B. decumbens and B. ruziziensis. The authors attributed the effect to the conditions of high N availability.…”

Section: 4 Aa -------------------Total-n (Mg Dm -3 ) ---------------supporting

confidence: 90%

Soil dynamic alterations and use efficiency of nitrogen by Brachiaria species

Castoldi¹,

Reis²,

Freiberger³

et al. 2017

Aust J Crop Sci

Self Cite

View full text Add to dashboard Cite

Under certain circumstances species of the Brachiaria genus, particularly B. humidicola might be able to suppress the biological nitrification in soil. This study aimed to investigate the ability of four Brachiaria species cultivated in Brazil to promote changes in the N dynamics in the soil as well as its capacity in use efficiently N under low N availability. In a greenhouse condition and using a Quartzipsamment soil, four species of Brachiaria (B. brizantha, B. decumbens, B. humidicola and B. ruziziensis) and two cut managements ("single cut" -performed at 140 days after seeding (DAS) and "cut/regrowth"-performed at 55 DAS and 85 days after the first cut (140 DAS)), plus a control treatment containing only soil were compared in a factorial design (4×2+1). The following evaluations were performed in plants: dry matter of shoots and roots, total N content, N accumulated and N use efficiency; and soil (which was split in rhizospheric and non-rhizospheric): ammonium, nitrate and total-N contents and pH value. Based on the soil inorganic-N content, there was no detectable effect of species in the soil nitrification process. Moreover, the highest ability of uptaking and using the N was observed in B. humidicola, which in the "single cut" management proved to be able to produce 201 g of shoot dry matter in response to each 1 g of N accumulated.

show abstract

“…In addition, it has been observed that nitrification was influenced in the rhizosphere of B. brizantha; however, this effect was not high enough to modify the N À NH 4 + level in the bulk soil (Fernandes et al, 2011). Therefore, it was concluded that in soil with abundant N supply none of the Brachiarias studied caused a significant effect on nitrification (Castoldi et al, 2013).…”

Section: N Losses Through Leaching Nitrous Oxide Emission and Ammonmentioning

confidence: 95%

“…K€ olln et al (2016) found that the root extracts of B. humidicola increased the initial growth of sugarcane plants but such an effect may as well be due to plant growth-promoting substances present in the root extracts because DCD, a synthetic nitrification inhibitor, did not produce the same effect. Castoldi et al (2013) measured the concentrations of inorganic N at several time intervals after desiccating plants of humidicola (B. humidicola, sin. Urochloa humidicola), palisade grass (Brachiaria brizantha, sin.…”

Section: N Losses Through Leaching Nitrous Oxide Emission and Ammonmentioning

confidence: 99%

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

Rosolem

Ritz

Cantarella

et al. 2017

Advances in Agronomy

View full text Add to dashboard Cite

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

show abstract

Soil nitrogen dynamics after Brachiaria desiccation

Cited by 12 publications

References 30 publications

Low 15N Natural Abundance in Shoot Tissue of Brachiaria humidicola Is an Indicator of Reduced N Losses Due to Biological Nitrification Inhibition (BNI)

Low 15N Natural Abundance in Shoot Tissue of Brachiaria humidicola Is an Indicator of Reduced N Losses Due to Biological Nitrification Inhibition (BNI)

Soil dynamic alterations and use efficiency of nitrogen by Brachiaria species

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

Contact Info

Product

Resources

About