Monitoring nutrient flows and economic performance in African farming systems (NUTMON).

Bosch, H. van den; Gitari, Josiah; Ogaro, V.N; Maobe, Samson; Vlaming, J.

doi:10.1016/s0167-8809(98)00132-7

Cited by 100 publications

(54 citation statements)

References 15 publications

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“…budgets and flows between the different production compartments, is scarce (Juo and Manu 1996;Kotto-Same et al 1997). Smaling et al (1996) and Van den Bosch et al (1998) presented the nutrient-monitoring concept, which considers five units within farms: crop production, animal production, household, stock or family store, and redistribution ( Figure 1). They considered six nutrient flows into the farm, i.e., inorganic fertilizers (IN1), organic inputs (IN2), wet and dry deposition (IN3), biological nitrogen fixation (IN4), sedimentation (IN5), and deep capture (IN6), and six outflows, i.e.…”

Section: Introductionmentioning

confidence: 99%

Nutrient flows in smallholder production systems in the humid forest zone of southern Cameroon

Kanmegne¹,

Brussaard

Gansop-Kouomegne

2006

Nutr Cycl Agroecosyst

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The flows and balances of N, P and K were studied in 20 farms in the Campo Ma'an area in Cameroon between March and August 2002 to assess the nutrient dynamics in smallholder farms. Data were collected through farmer interviews, field measurements and estimates from transfer functions. Nutrient input from mineral (IN1), animal feed (IN2a) and inorganic amendments (IN2b) was absent. Major outputs were through crop (OUT1a) and animal (OUT1b) products sold. Partial budgets for farmer managed flows were negative: À65 kg N, À5.5 kg P and À30.8 kg K ha À1 year À1 . For inflows not managed by farmers, deep capture (IN6) was the major source: 16.6, 1.4 and 6.6 kg ha À1 year À1 of N, P and K, respectively. Atmospheric deposition (IN3) was estimated at 4.3 kg N, 1.0 kg P and 3.9 kg K ha À1 year À1 , and biological nitrogen fixation (IN4) at 6.9 kg N ha À1 year À1 . Major losses were leaching (OUT 3a): 26.4 kg N, and 0.88 kg K ha À1 year À1 . Gaseous losses from the soil (OUT 4a) were estimated at 6.34 kg N, and human faeces (OUT 6) were estimated at 4 kg N, 0.64 kg P and 4.8 kg K ha À1 year À1 . The highest losses were from burning (OUT 4c), i.e. 47.8 kg N, 1.8 kg P and 14.3 kg K ha À1 year À1 . Partial budgets of environmentally controlled flows were negative only for N À4.8 kg N, +2.4 kg P and +9.6 kg K ha À1 year À1 . The overall farm budgets were negative, with annual losses of 69 kg N, 3 kg P and 21 kg K ha À1 . Only cocoa had a positive nutrient balance: +9.3 kg N, +1.4 kg P and +7.6 kg K ha À1 year À1 . Nutrients reaching the household waste (1.9 kg N, 2.8 kg P and 18.8 kg K ha À1 year À1 ), animal manure (4.9 kg N, 0.4 kg P and 1.6 kg K), and human faeces (4 kg N, 0.64 kg P and 4.8 kg K ha À1 year À1 ) were not recycled. Five alternative management scenarios were envisaged to improve the nutrient balances. Recycling animal manure, household waste and human faeces will bring the balance at À62.6 kg N, 0 kg P and +1 kg K ha À1 year À1 . If, additionally, burning could be avoided, positive nutrient balances could be expected.

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Section: Introductionmentioning

confidence: 99%

Nutrient flows in smallholder production systems in the humid forest zone of southern Cameroon

Kanmegne¹,

Brussaard

Gansop-Kouomegne

2006

Nutr Cycl Agroecosyst

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“…The interpretation of the nutrient balances can be further improved by linking the farm nutrient budgets with total soil nutrient stocks (Van den Bosch et al 1998). Data collection for reliable parameterization of the model was time-consuming.…”

Section: Discussionmentioning

confidence: 99%

“…Nutmon uses a conceptual model that distinguishes various compartments on the farm including farm section units (FSU), primary production units (PPU), secondary production units (SPU), redistribution units (RU), the household (HH), stocks (STOCK), and the external world (EXT) (see Van den Bosch et al 1998;De Jager et al 1998 for a full description). Land resources are described by FSUs which are land units that are considered homogeneous with well described characteristics.…”

Section: Nutmonmentioning

confidence: 99%

“…Nutmon considers five nutrient inputs: IN1 (inorganic fertilizers and feed concentrates), IN2 (organic feeds and organic materials), IN3 (atmospheric deposition), IN4 (nitrogen fixation), and IN5 (sedimentation), and five outflows: OUT1 (crop and animal products), OUT2 (plant/crop residues and manure), OUT3 (leaching), OUT4 (gaseous losses), and OUT5 (erosion and overland flow). Nutmon quantifies the various nutrient flows in two different ways (Van den Bosch et al 1998). The so-called easy-to-quantify nutrient flows (IN1, IN2, OUT1, and OUT2) are directly assessed during a dynamic farm survey.…”

Section: Nutmonmentioning

confidence: 99%

“…Other flows like nitrogen fixation, leaching, and erosion are more difficult to measure and are estimated by means of regression models. Nutmon is originally developed for African farming systems (Stoorvogel and Smaling 1990;Smaling and Fresco 1993;De Jager et al 1998; Van den Bosch et al 1998;Vlaming et al 2001) where numerous studies have been carried out in Kenya (De Jager et al 1998; Van den Bosch et al 1998;Gachimbi et al 2002;Muendo 2006), Ethiopia (Abegaz 2005), Uganda and Burkina Faso (Agwe et al 2007). These studies in SubSaharan Africa reveal, almost unequivocally, alarming nutrient depletion rates (Stoorvogel 2007).…”

Section: Introductionmentioning

confidence: 99%

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Modeling the soil nutrient balance of integrated agriculture-aquaculture systems in the Mekong Delta, Vietnam

Phong

Stoorvogel

Mensvoort

et al. 2010

Nutr Cycl Agroecosyst

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This study quantifies soil nutrient balances of Integrated Agriculture-Aquaculture Systems in the Mekong Delta of Vietnam. Eleven farms were monitored to collect data on farm activities and nutrient inputs and outputs to compute these balances of the rice-based and high input fish system in O Mon district (R-HF); the rice-based and medium input fish system in Tam Binh district (R-MF); and the orchardbased and low input fish system in Cai Be district (O-LF). For the estimation, the Nutmon model has been adapted to the specific conditions in these integrated systems in Asia (Nutmon-Asia). New regression models of leaching and gaseous losses of nitrogen were applied to fields used for upland crops and paddy rice. Reference values were used for the assessment of nitrogen fixation in paddy soils, wet atmospheric deposition, and irrigation water. The results showed that farms in all three systems have nitrogen, phosphorus and potassium surpluses (84 kg N, 73 kg P, and 69 kg K ha -1 year -1 ). The O-LF system had the smallest nitrogen surplus while the smallest surplus of phosphorus and potassium was seen in the R-HF system. High surpluses of phosphorus and potassium were found in vegetable fields, whereas a negative potassium balance was found in the rice fields of all three systems. The positive farm nutrient balances indicate that it is likely that soil fertility will be maintained although there is a risk for environmental contamination.

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Assessment of the impact of water erosion on productivity of maize in Kenya: an integrated modelling approach

Mantel

Engelen

1999

Land Degrad. Dev.

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Monitoring nutrient flows and economic performance in African farming systems (NUTMON).

Cited by 100 publications

References 15 publications

Nutrient flows in smallholder production systems in the humid forest zone of southern Cameroon

Nutrient flows in smallholder production systems in the humid forest zone of southern Cameroon

Modeling the soil nutrient balance of integrated agriculture-aquaculture systems in the Mekong Delta, Vietnam

Assessment of the impact of water erosion on productivity of maize in Kenya: an integrated modelling approach

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