Potential of East African phosphate rock deposits in integrated nutrient management strategies

Jama, Bashir; Straaten, Peter van

doi:10.1590/s0001-37652006000400012

Cited by 25 publications

(16 citation statements)

References 12 publications

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“…Acidulated P fertilizers such as triple super phosphate (TSP) offer soluble and rapidly available P, but access and affordability limit their use by smallholder farmers (Jama and Kiwia 2009;Nziguheba et al 2016). In many parts of sub-Saharan Africa, phosphate rock deposits are an economical alternative to TSP (Jama and Van Straaten 2006;Nandwa and Bekunda 1998). The largest high-quality deposit of PR (10 7 t) in East Africa is Minjingu phosphate rock (PR) (Van Kauwenbergh 1991;van Straaten 2002).…”

Section: Introductionmentioning

confidence: 99%

Biological P cycling is influenced by the form of P fertilizer in an Oxisol

et al. 2017

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Phosphate rock (PR) is an alternative fertilizer to increase the P content of P-deficient weathered soils. We evaluated the effects of fertilizer form on indicators of biological cycling of P using an on-farm trial on a Rhodic Kandiudox in western Kenya. Treatment plots were sampled after 13 cropping seasons of P applications as Minjingu phosphate rock (PR) or as triple super phosphate (TSP) (50 kg P ha −1 season −1 ), as well as a P-unfertilized control (0 kg P ha −1 season −1 ). Soils (0-15 and 15-30 cm) were analyzed for microbial biomass P (P mic ), activities of acid phosphomonoesterase, alkaline phosphomonoesterase, and phosphodiesterase, and sequentially extractable P fractions. P additions as Minjingu PR yielded 299% greater P mic than TSP at 0-15-cm depth despite similar labile P concentrations in the two P fertilization treatments and stimulated activities of acid phosphomonoesterase (+39%). When added in the soluble form of TSP, a greater percentage of total soil P was present in mineral-bound forms (+33% Fe-and Al-associated P). Higher soil pH under Minjingu PR (pH 5.35) versus TSP (pH 5.02) and the P-unfertilized treatment (pH 4.69) at 0-15-cm depth reflected a liming effect of Minjingu PR. The form of P fertilizer can influence biological P cycling in weathered soils, potentially improving P availability under Minjingu PR relative to TSP via enhanced microbial biomass P and enzymatic drivers of P cycling.

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Section: Introductionmentioning

confidence: 99%

Biological P cycling is influenced by the form of P fertilizer in an Oxisol

et al. 2017

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“… Effects of improved fallows and Minjingu phosphate rock on maize grain yield under farmers' management conditions in western Kenya 38 …”

Section: Approaches To Soil Fertility Improvementmentioning

confidence: 99%

Agriculture in Africa: Strategies to Improve and Sustain Smallholder Production Systems

Jama

Pizarro

2008

Annals of the New York Academy of Sciences

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Agricultural development lies at the heart of poverty reduction and increased food security of most developing nations. Sub-Saharan Africa (hereafter referred to as Africa) is, however, the only region in the world where per capita agricultural productivity has remained stagnant over the past 40 years. In Asia and Latin America, the use of tailored techniques and technologies has transformed agricultural practice and its productivity, leading to what has been called the "green revolution." The dissemination of uniquely African green revolution technologies has not occurred on the continent. This chapter will argue that the same results in increased productivity and food security can be achieved in Africa if the appropriate investments are made in key interventions: soil fertility improvement, improved seeds, water management, market access, extension services, access to credit, and improvements in weather forecasting. Where these have happened, even partially, the outcome has been remarkable. However, bringing them to scale in ways that sustainably increase agricultural productivity and alleviate poverty requires increased investments and innovative institutional arrangements. Fortunately, several research and development projects on the continent, including the Millennium Villages Project, are providing valuable insights. Finally, this chapter outlines the key remaining challenges.

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“…Plants need nitrogen, phosphorus, and potassium, as well as micronutrients and symbiotic relationships with fungi and other organisms to flourish, but getting enough nitrogen, and particularly synchronization so that plants get enough nitrogen when they need it most, is likely the greatest challenge for organic farmers (Makinde & Ayoola, 2010;Tunstall, 2008). Organic farmers also use animal manure, certain processed fertilizers such as seed meal and various mineral powders such as indigenous rock phosphate (Jama & Van Straaten, 2006;Van Straaten, 2002) and greensand, a naturally occurring form of potash which provides potassium, to maintain soil fertility (Lal, 2003). Among the common organic manures in use in fertility management of soils in Kenya are poultry manure, cattle dung, swine dung and goat dung.…”

Section: Introductionmentioning

confidence: 99%

Effect of Applying Organic Amendments and Chickpea Integration on Soil Chemical Properties in Different Cropping Systems in Central Kenya

Ndukhu¹,

Wahome²,

Jensen³

2018

JAS

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A study was carried out to determine the effect of applying farm yard manure (FYM) and Minjingu rock phosphate (MRP) on soil available nitrogen, phosphorus and organic carbon. The study involved field experiments under varying precipitation pattern, soil fertility levels and cropping systems over four growth seasons. The experimental design was a randomized complete block (RCBD) with four replications in a split plot arrangement where the main plots were the three cropping systems; monocropping, intercropping and crop rotation and the split plots were FYM and MRP and sampling done at crop physiological maturity. Soil pH, N, P K and C increased in the different treatments in the following order control < MRP < FYM in the three cropping systems across the four growing seasons at both sites. In maize under rotation with chickpea control had; 0.281% N, 2.82% C and 10.68 ppm P. FYM; 0.554% N, 4.41% C and18.24 ppm P. MRP; 0.45% N, 3.6% C and 41.08 ppm P. Maize chickpea intercrop control; 0.389% N, 3.192% C and 13.4 ppm P. FYM; 0.531% N, 4.98% C and 41.02 ppm P. MRP; 0.49% N, 4.08% C and 50.9 ppm P. Soil under maize monocrop exhibited; control; 0.2% N, 2.59% C and11.26 ppm P. FYM; 0.416% N, 3.83% C and 18.01 ppm P. MRP; 0.28% N, 3.13% C and 26.1ppm P. Almost a similar trend was observed in maize and tomato plots at both sites in all the growing seasons. Thus it can be deduced that, FYM and MRP application and legume integration in cropping systems improves soil fertility.

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Potential of East African phosphate rock deposits in integrated nutrient management strategies

Cited by 25 publications

References 12 publications

Biological P cycling is influenced by the form of P fertilizer in an Oxisol

Biological P cycling is influenced by the form of P fertilizer in an Oxisol

Agriculture in Africa: Strategies to Improve and Sustain Smallholder Production Systems

Effect of Applying Organic Amendments and Chickpea Integration on Soil Chemical Properties in Different Cropping Systems in Central Kenya

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