Cite as:
Bahr, E.; Chamba Zaragocin, D.; Fierro Jaramillo, N.; Witt, A. &amp; Makeschin, F. (2014): <b>Modeling of soil nutrient balances, flows and stocks revealed effects of management on soil fertility in south Ecuadorian smallholder farming systems</b>. <i>Nutrient Cycling in Agroecosystems</i> <b>-</b>, -.

Resource Description

Title: Modeling of soil nutrient balances, flows and stocks revealed effects of management on soil fertility in south Ecuadorian smallholder farming systems
FOR816dw ID: 1308
Publication Date: 2014-11-21
License and Usage Rights: PAK 823-825 data user agreement. (
Resource Owner(s):
Individual: Etienne Bahr
Individual: Diego Chamba Zaragocin
Individual: Natacha Fierro Jaramillo
Individual: Anke Witt
Individual: Franz Makeschin
Linking nutrient balances and flows to soil<br/> nutrient stocks creates a valuable indicator for sustainability<br/> assessment in agricultural land-use systems.<br/> Therefore, we investigated the impact of management<br/> on soil fertility at farm/field scale using the Nutmon<br/> approach. A detailed methodology for the adaptation<br/> of the difficult-to-quantify flows to the local conditions<br/> is described. Research was carried out in the three<br/> farming systems of Yantzaza (low-external-input), El<br/> Tambo (irrigated cash crops) and San Lucas (integrated<br/> nutrient management) in southern Ecuador. For<br/> each land-use within a farm (annual and perennial<br/> crops, pasture, forest), soil nutrient balances and flows<br/> were modeled with Nutmon and soil nutrient stocks<br/> were calculated for NPK. Soil nutrient balances were<br/> evaluated using potential socio-economic and soil<br/> fertility explanatory variables. Balances for the different<br/> land-uses in the three research areas varied between<br/> -151 to 66 kg ha-1 a-1 for N, -4 to 33 kg ha-1 a-1 for P and -346 to 39 kg ha-1 a-1 for K and were mainly negative. Up to 70 % of the balances’ variability was explained by soil fertility variables and financial flows. Highest external inputs existed in<br/> land-uses with a strong market orientation. Land-uses<br/> benefiting from a surplus of within-farm flows had the<br/> highest soil nutrient stocks. The focus on N fertilization<br/> induced highly negative PKbalances in annual crops of<br/> El Tambo. In contrast, the application of organic<br/> fertilizers and nutrient recycling in San Lucas resulted<br/> in positive NP balances particularly for perennial<br/> crops. NP balances in annual crops of Yantzaza were<br/> most negative due to nonexistent fertilization, leaching<br/> and burning of crop residues. A non-sustainable landuse<br/> of annual crops in Yantzaza was illustrated by total<br/> N stock decreases of 4.9 % a-1 and decreased soil<br/> organic carbon stocks to 85 % of adjacent forest sites.<br/> Results indicated a potential risk regarding sustainable<br/> management of soils in the research area and provide a<br/> basis for policy and decision makers to develop<br/> appropriate management strategies.
| soil nutrient depletion | Nutmon | agricultural soil | sustainable land-use | within-farm flows |
Literature type specific fields:
Journal: Nutrient Cycling in Agroecosystems
Volume: -
Page Range: -
Publisher: Springer
ISSN: 1573-0867
Metadata Provider:
Individual: Etienne Bahr
Online Distribution:
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