Comparison of partial and complete soil K budgets under intensive rice cropping in the Mekong Delta, Vietnam

Hoa, Nguyen My; Janssen, B.H.; Oenema, O.; Dobermann, A.

doi:10.1016/j.agee.2006.03.020

Cited by 40 publications

(27 citation statements)

References 9 publications

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“…K is required in large amounts for growing crops, but farmers in poor countries often do not fertilize with K due to high costs, which leads to K deficiencies in large areas of farmland (Hoa et al, 2006;Andrist-Rangel et al, 2007). The situation is especially critical in Africa.…”

Section: Anthropogenic Impacts On the K Cycle K Fertilizersmentioning

confidence: 99%

Potassium: a neglected nutrient in global change

Sardans

Peñuelas

2015

Global Ecology and Biogeography

436

283

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Aim Potassium (K) is the second most abundant nutrient in plant photosynthetic tissues after nitrogen (N). Thousands of physiological and metabolic studies in recent decades have established the fundamental role of K in plant function, especially in water-use efficiency and economy, and yet macroecological studies have mostly overlooked this nutrient. MethodsWe have reviewed available studies on the content, stoichiometry and roles of K in the soil-plant system and in terrestrial ecosystems. We have also reviewed the impacts of global change drivers on K content, stoichiometry and roles. ConclusionsThe current literature indicates that K, at a global level, is as limiting as N and phosphorus (P) for plant productivity in terrestrial ecosystems. Some degree of K limitation has been seen in up to 70% of all studied terrestrial ecosystems. However, in some areas atmospheric K deposition from human activities is greater than that from natural sources. We are far from understanding the K fluxes between the atmosphere and land, and the role of anthropogenic activities in these fluxes. The increasing aridity expected in wide areas of the world makes K more critical through its role in water-use efficiency. N deposition exerts a strong impact on the ecosystem K cycle, decreasing K availability and increasing K limitation. Plant invasive success is enhanced by higher soil K availability, especially in environments without strong abiotic stresses. The impacts of other drivers of global change, such as increasing atmospheric CO2 or changes in land use, remain to be elucidated. Current models of the responses of ecosystems and carbon storage to projected global climatic and atmospheric changes are now starting to consider N and P, but they should also consider K, mostly in arid and semi-arid ecosystems.

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Section: Anthropogenic Impacts On the K Cycle K Fertilizersmentioning

confidence: 99%

Potassium: a neglected nutrient in global change

Sardans

Peñuelas

2015

Global Ecology and Biogeography

436

283

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“…In the VMD, sediment deposition is known to especially provide Potassium (K), a staple fertiliser in rice agriculture (Hoa et al 2006). Manh et al (2014) estimate that the annual deposition of sediment-bound nutrients can supply over half of the fertilisation (N, P, K) needed for a season of rice agriculture.…”

Section: Study Areamentioning

confidence: 99%

Adaptation and development trade-offs: fluvial sediment deposition and the sustainability of rice-cropping in An Giang Province, Mekong Delta

et al. 2016

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Deltas around the globe are facing a multitude of intensifying environmental change and development-linked pressures. One key concern is the reduction in the quantity of suspended sediment reaching and building floodplains. Sediment deposition provides multiple services to deltaic social-ecological systems, in particular, countering the subsidence of the delta-body, and providing plentiful nutrients. Experiencing particularly rapid change is the Vietnamese Mekong Delta (VMD). In An Giang Province an increasing number of high dyke rings, which exclude the flood and facilitate triple rice-cropping, simultaneously prevent much of the sediment load from reaching the floodplain. This paper explores the trade-offs implicit in the decision to shift from (i) doublecropping (higher sediment deposition) to (ii) triple cropping (lower sediment deposition) by asking: what is the impact of the shift on VMD farmers? Is it sustainable? And what is the significance of the associated sediment exclusion? A novel survey of An Giang rice farmers was conducted, investigating key agricultural practices, and uniquely, the farmers' estimates of annual sediment deposition depth. The survey elicits some key changes under the adapted system (ii), particularly, unsustainable trajectories in the yield to fertiliser ratio which penalise land-poor farmers. Furthermore, the value (to farmers) of the sediment contribution to agricultural fertilisation which is lost due to triple-cropping is estimated at USD 15 (±5) million annually. We argue that our growing understanding of the importance of sediment in the deltaic social-ecological system may be revealing an emergent risk; arising from conflicting long and short-term adaptation and agricultural development objectives.

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“…Except for some minor hilly areas, the MD is flat and low-lying with an average altitude of about 2 meters above sea level (Hoa 2003). The MD has a tropical monsoon climate with an average annual temperature of 27.2°C.…”

Section: Study Sites and Farm Selectionmentioning

confidence: 99%

“…In IAA farms the fruit trees and vegetables are irrigated with a frequency of 3 days in the dry season (i.e., 6 months). Based on Nhan et al (2006) and Hoa et al (2006), irrigation water in IAA farms is estimated to contribute 1.8 kg N, 2.4 kg P, and 1.2 kg K ha -1 year -1 . For one rice crop (i.e., 3 months) the irrigation water supplies 2.7 kg N, 3.6 kg P, and 1.8 kg K ha -1 .…”

Section: Sedimentation and Irrigation (In5)mentioning

confidence: 99%

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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Comparison of partial and complete soil K budgets under intensive rice cropping in the Mekong Delta, Vietnam

Cited by 40 publications

References 9 publications

Potassium: a neglected nutrient in global change

Potassium: a neglected nutrient in global change

Adaptation and development trade-offs: fluvial sediment deposition and the sustainability of rice-cropping in An Giang Province, Mekong Delta

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

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