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Optimizing interaction between crop residues and inorganic N under zero tillage systems in sub-humid region of Kenya

Conservation agriculture practices involving zero tillage and residue retention are promising nutrient management strategies for soil health restoration. Despite their potential positive impact on soil fertility, improved crop yields and increased revenues for smallholder farmers; their effect on ni...

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Autores principales: Michael, Kinyua, Monicah, Mucheru-Muna, Peter, Bolo, Job, Kihara
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Elsevier 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8449170/
https://www.ncbi.nlm.nih.gov/pubmed/34568593
http://dx.doi.org/10.1016/j.heliyon.2021.e07908
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author Michael, Kinyua
Monicah, Mucheru-Muna
Peter, Bolo
Job, Kihara
author_facet Michael, Kinyua
Monicah, Mucheru-Muna
Peter, Bolo
Job, Kihara
author_sort Michael, Kinyua
collection PubMed
description Conservation agriculture practices involving zero tillage and residue retention are promising nutrient management strategies for soil health restoration. Despite their potential positive impact on soil fertility, improved crop yields and increased revenues for smallholder farmers; their effect on nitrogen inputs and crop growth is not clearly understood. This may limit their potential as a nutrient management strategy that may remedy soil degradation and boost crop yields for farmers. This study investigated how different tillage practices, crop residues and inorganic nitrogen (N) options affect maize production, soil fertility and economics of smallholder farming systems. The study was conducted in a short-term (2 years) on-station trial, under randomized complete block design with three replications in a maize monocrop system. Six treatments, involving three different rates of maize stover residue (0, 3 and 5 t ha(−1)) and inorganic N (0, 3 and 5 t ha(−1)) inputs, respectively, were assessed under conventional and zero tillage systems. Mineral N and organic C were assessed at four depths (0–10 cm, 10–30 cm, 30–60 cm and 60–90 cm) whereas soil aggregate distribution was assessed at 0–5 cm, 5–10 cm, 10–15 cm and 15–20 cm depths. Application of inorganic N as the only input increased (p ≤ 0.05) grain yield (with the yields doubling in the short rains (SR) of 2015 and increasing by 1.4 times in long rains (LR) of 2016) compared to unfertilized control treatment. Treatment, soil depth and the time of sampling significantly affected soil mineral N concentration (p ≤ 0.05). Soil organic C reduced significantly (p ≤ 0.05) with sampling depths, but no differences were observed across treatments. At 0–5 cm depth, the proportion of large macroaggregates in zero tillage increased (48%; p ≤ 0.05) after application of crop residues at 5 t ha(−1) relative to 3 t ha(−1). Zero tillage treatment with application of 5 t ha(−1) of residue and 80 kg N ha(−1) was the most dominant and most profitable compared to the other treatments. This treatment had a benefit cost ratio (BCR) of 2.9 (in the short rains season of 2015) and 3.0 (long rains of 2016 seasons). Its marginal rate of return (MRR) was 368% (in the 2015 short rains season) and 416% (in the 2016 long rains season). This makes it a good nutrient management strategy with potential of optimizing maize yields.
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spelling pubmed-84491702021-09-24 Optimizing interaction between crop residues and inorganic N under zero tillage systems in sub-humid region of Kenya Michael, Kinyua Monicah, Mucheru-Muna Peter, Bolo Job, Kihara Heliyon Research Article Conservation agriculture practices involving zero tillage and residue retention are promising nutrient management strategies for soil health restoration. Despite their potential positive impact on soil fertility, improved crop yields and increased revenues for smallholder farmers; their effect on nitrogen inputs and crop growth is not clearly understood. This may limit their potential as a nutrient management strategy that may remedy soil degradation and boost crop yields for farmers. This study investigated how different tillage practices, crop residues and inorganic nitrogen (N) options affect maize production, soil fertility and economics of smallholder farming systems. The study was conducted in a short-term (2 years) on-station trial, under randomized complete block design with three replications in a maize monocrop system. Six treatments, involving three different rates of maize stover residue (0, 3 and 5 t ha(−1)) and inorganic N (0, 3 and 5 t ha(−1)) inputs, respectively, were assessed under conventional and zero tillage systems. Mineral N and organic C were assessed at four depths (0–10 cm, 10–30 cm, 30–60 cm and 60–90 cm) whereas soil aggregate distribution was assessed at 0–5 cm, 5–10 cm, 10–15 cm and 15–20 cm depths. Application of inorganic N as the only input increased (p ≤ 0.05) grain yield (with the yields doubling in the short rains (SR) of 2015 and increasing by 1.4 times in long rains (LR) of 2016) compared to unfertilized control treatment. Treatment, soil depth and the time of sampling significantly affected soil mineral N concentration (p ≤ 0.05). Soil organic C reduced significantly (p ≤ 0.05) with sampling depths, but no differences were observed across treatments. At 0–5 cm depth, the proportion of large macroaggregates in zero tillage increased (48%; p ≤ 0.05) after application of crop residues at 5 t ha(−1) relative to 3 t ha(−1). Zero tillage treatment with application of 5 t ha(−1) of residue and 80 kg N ha(−1) was the most dominant and most profitable compared to the other treatments. This treatment had a benefit cost ratio (BCR) of 2.9 (in the short rains season of 2015) and 3.0 (long rains of 2016 seasons). Its marginal rate of return (MRR) was 368% (in the 2015 short rains season) and 416% (in the 2016 long rains season). This makes it a good nutrient management strategy with potential of optimizing maize yields. Elsevier 2021-09-11 /pmc/articles/PMC8449170/ /pubmed/34568593 http://dx.doi.org/10.1016/j.heliyon.2021.e07908 Text en © 2021 The Authors https://creativecommons.org/licenses/by-nc-nd/4.0/This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
spellingShingle Research Article
Michael, Kinyua
Monicah, Mucheru-Muna
Peter, Bolo
Job, Kihara
Optimizing interaction between crop residues and inorganic N under zero tillage systems in sub-humid region of Kenya
title Optimizing interaction between crop residues and inorganic N under zero tillage systems in sub-humid region of Kenya
title_full Optimizing interaction between crop residues and inorganic N under zero tillage systems in sub-humid region of Kenya
title_fullStr Optimizing interaction between crop residues and inorganic N under zero tillage systems in sub-humid region of Kenya
title_full_unstemmed Optimizing interaction between crop residues and inorganic N under zero tillage systems in sub-humid region of Kenya
title_short Optimizing interaction between crop residues and inorganic N under zero tillage systems in sub-humid region of Kenya
title_sort optimizing interaction between crop residues and inorganic n under zero tillage systems in sub-humid region of kenya
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8449170/
https://www.ncbi.nlm.nih.gov/pubmed/34568593
http://dx.doi.org/10.1016/j.heliyon.2021.e07908
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