Potassium in Two Humid Tropical Ultisols under a Corn and Soybean Cropping System: I. Management

Cox, F. R.; Uribe, E.

doi:10.2134/agronj1992.00021962008400030024x

Cited by 6 publications

(2 citation statements)

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“…No K fertilizer was applied at this site. Soybean has a high K demand (Cox and Uribe, 1992), and most K taken up moves to the roots by a diffusion gradient, a process that can be impeded by dry soil conditions (Haby et al, 1990). The drought conditions in 2002 may have exacerbated any soil K differences in these fields (soybean tissue was not analyzed for K).…”

Section: Resultsmentioning

confidence: 99%

Can a Labile Carbon Test be Used to Predict Crop Responses to Improve Soil Organic Matter Management?

2012

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Permanganate (KMnO4) oxidizable C (POXC), an estimate of labile soil C, was evaluated for use as a soil test to identify soils that may respond positively to soil organic matter (SOM) management. We hypothesized that soils lower in POXC would be more likely than soils higher in POXC to show increased crop productivity in response to practices that increase SOM. At four sites, paired fields of the same soil but contrasting management history (cropping vs. sod) were studied. Fields with sod history tested higher in total organic C (TOC) and POXC than fields with cropped history. Permanganate‐oxidizable C was strongly related to TOC (r = 0.94). We examined crop stover, grain, and biomass responses to two cover crop treatments within each field: winter rye (Secale cereale L.) or no rye. After at least 1 yr of treatment, there was a significant negative correlation between relative stover response to rye and POXC (r = –0.60) at sites with finer textured soils. After at least 2 yr of treatment, crop responses to rye showed a significant negative correlation with POXC and TOC. The strongest relationships to POXC occurred in the stover response at two sites with finer textured soils (Keedysville: r = –0.74; Holtwood: r = –0.84). Permanganate‐oxidizable C was comparable to TOC at predicting crop responses to rye. These results suggest that POXC may be a useful test for identifying soils where improved SOM management is likely to improve productivity. The rapid, simple POXC methodology enables on‐site or laboratory soil testing.

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Section: Resultsmentioning

confidence: 99%

Can a Labile Carbon Test be Used to Predict Crop Responses to Improve Soil Organic Matter Management?

2012

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“…Regarding soil K, we assumed that after addition of fertilizers, exchangeable K returns to its previous ‘base level’ within 1 year after application, similar to findings of e.g. Cox & Uribe (1992).…”

Section: Methodsmentioning

confidence: 99%

The production‐ecological sustainability of cassava, sugarcane and sweet sorghum cultivation for bioethanol in Mozambique

et al. 2011

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We present an approach for providing quantitative insight into the production-ecological sustainability of biofuel feedstock production systems. The approach is based on a simple crop-soil model and was used for assessing feedstock from current and improved production systems of cassava for bioethanol. Assessments were performed for a study area in Mozambique, a country considered promising for biomass production. Our focus is on the potential role of smallholders in the production of feedstock for biofuels. We take cassava as the crop for this purpose and compare it with feedstock production on plantations using sugarcane, sweet sorghum and cassava as benchmarks. Productionecological sustainability was defined by seven indicators related to resource-use efficiency, soil quality, net energy production and greenhouse gas (GHG) emissions. Results indicate that of the assessed systems, sugarcane performed better than cassava, although it requires substantial water for irrigation. Targeted use of nutrient inputs improved sustainability of smallholder cassava. Cassava production systems on more fertile soils were more sustainable than those on less fertile soils; the latter required more external inputs for achieving the same output, affecting most indicators negatively and reducing the feasibility for smallholders. Cassava and sweet sorghum performed similarly. Cassava production requires much more labour per hectare than production of sugarcane or sweet sorghum. Production of bioethanol feedstock on cultivated lands was more sustainable and had potential for carbon sequestration, avoiding GHG emissions from clearing natural vegetation if new land is opened.

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Soil test modifiers for coarse‐textured calcareous soils

Amer

1995

Communications in Soil Science and Plant Analysis

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Potassium in Two Humid Tropical Ultisols under a Corn and Soybean Cropping System: I. Management

Cited by 6 publications

References 0 publications

Can a Labile Carbon Test be Used to Predict Crop Responses to Improve Soil Organic Matter Management?

Can a Labile Carbon Test be Used to Predict Crop Responses to Improve Soil Organic Matter Management?

The production‐ecological sustainability of cassava, sugarcane and sweet sorghum cultivation for bioethanol in Mozambique

Soil test modifiers for coarse‐textured calcareous soils

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