Nitrogen balance in response to dryland crop rotations and cultural practices

Abstract

A B S T R A C TNitrogen balance provides a measure of agroecosystem performance and environmental sustainability by taking into accounts of N inputs and outputs and N retention in the soil. The objective of this study was to evaluate N balance based on N inputs and outputs and soil N sequestration after 7 yr in response to five dryland crop rotations (two 4-yr stacked and two 4-yr alternate-year rotations and one monocropping) and two cultural practices arranged in a split-plot design in the northern Great Plains, USA. Stacked. Alternate-year rotations were durum-canola-durum-pea (D-C-D-P) and durum-flax-durum-pea (D-F-D-P). Monocroppping was continuous durum (CD). Cultural practices were traditional (conventional till, recommended seed rate, broadcast N fertilization, and reduced stubble height) and ecological (no-till, increased seed rate, banded N fertilization, and increased stubble height). Total annual N input due to N fertilization, pea N fixation, atmospheric N deposition, crop seed N, and nonsymbiotic N fixation was lower in CD than other crop rotations, regardless of cultural practices. Total N output due to crop grain N removal and N losses due to denitrification, volatilization, plant senescence, N leaching, gaseous N (NO for ecological D-D-F-P to 52 kg N ha À1 yr À1 for ecological CD. Nitrogen balance ranged from À39 to À36 kg N ha À1 yr À1 with CD compared to 9-25 kg N ha À1 yr À1 with other crop rotations in both cultural practices. Because of reduced reliance on external N inputs and increased grain N removal, N flow, and N surplus, crop rotations with legumes, nonlegumes, and oilseed crops in the rotation can be productive and environmentally sustainable compared with monocropping, regardless of cultural practices. Published by Elsevier B.V.

Corn agronomic traits and recovery of nitrogen from fertilizer during crop season and off-season

“…However, the continue cultivation without N fertilizations may deplete SOM over time and, consequently, the soil-N supply (Davis et al, 2003). Nonetheless, the absence of N-fertilizer rates in the fall-winter season can be considered a sustainable alternative, especially if crop rotation is applied with Leguminosae plants, which can improve the soil-N supply due to N fixation in the spring-summer (Sainju et al, 2016).…”

Soil Biological Fertility and Bacterial Community Response to Land Use Intensity: A Case Study in the Mediterranean Area

“…These findings highlight the need for proper sustainable land management to prevent soil degradation [50], since the sustainability of the dryland ecosystem and its agricultural production depends strongly on proper and effective land-use and management [51]. Thus, it is quite clear that the conventional tillage with the crop-fallow system should be avoided in dryland cropping systems because of consequently reduced soil fertility and degraded chemical properties [52].…”

Diagnóstico do uso e conservação do solo em região de reforma agrária no semiárido

“…Souza et al (2011), trabalhando com milho e feijão no semiárido paraibano, chegaram à conclusão de que, mesmo quando a produtividade das culturas cultivadas separadamente é maior, a adoção do consórcio deve ser estimulada, pois se trata de uma atividade vantajosa economicamente. Temesgen et al (2015), estudando o rendimento das culturas (milho e feijão) na Austrália, conforme a disponibilidade de recursos da área, verificaram que o sistema de consórcio milho-feijão foi superior para produção de biomassa total, grãos e produção de energia, sendo significativamente maior do que o feijão quando cultivado exclusivamente Do ponto de vista da conservação do solo, o sistema de consórcio entre gramínea (milho) e leguminosa (feijão) é benéfico à fertilidade do solo, pois a leguminosa pode fixar nitrogênio (N) atmosférico por meio de bactérias que habitam suas raízes, enriquecendo o solo quanto aos teores desse nutriente (SAINJU et al, 2016). Contudo, nas propriedades do assentamento estudado, como os grãos de feijão são colhidos na área, nem todo nitrogênio fixado é adicionado ao solo.…”