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Rock phosphate doubles crop for Elishililia

Arusha, Tanzania

To celebrate International Women’s Day the African Soil Health Consortium (ASHC) shares a good news story of fertilizer innovation in Tanzania. The impact of a new locally produced rock phosphate fertilizer, Minjingu, has been made all the more powerful as part of an integrated soil fertility management (ISFM) approach: new seed varieties and the use of organic fertilizers combined with the rock phosphate haves led to small scale farmers’ crop yields more than doubling…

Case study

In November 2011 the ASHC team found Ms Elishililia Alex’s in high spirits when they visited her small-scale farm in Arusha, Tanzania. Unexpected rains and a robust maize crop at just six weeks were both good news.

Elishililia is a small-scale farmer. She intercrops maize, pigeon pea and common beans. Along with other farmers and agro-dealers in her community, Elishililia received training from Selian Agricultural Research Institute (SARI) agricultural officers at village level.

Using a new of pigeon pea variety that matures quickly her yield more than tripled from 1-2 bags per acre to 5 or 6 bags of pigeon pea per acre. This fetches her about Tsh 82,500 per bag (US$ 52). The agricultural officers also advocated applying manure before planting, Minjingu when planting and urea when top dressing.

“I have been a widow for six years” Elishililia explained. “I have educated my children through farming and built a permanent house. If you have farm animals which provide manure, prepare your land well, and use good seeds and fertilizer you will get a good harvest.

This season I planted maize and pigeon peas and applied Minjingu. Although pests destroyed the pigeon pea, the maize looks good.

Last season I harvested 8 bags of maize per acre where there was Minjingu. But, in another farm I didn’t plant with Minjingu and only harvested 3 bags, which could have been more had rains come on time.”

Elishililia is one of 30,000 farmers in the Northern and Eastern Zones, and Southern Highlands of Tanzania who are being encouraged to use Minjingu. Using communication products provided by agricultural research institutes and fertilizer companies like leaflets and brochures they learn how to plant new varieties, applying fertilizers and herbicides, storage of produce, among other relevant topics.

Elishililia’s farm is one of the demonstration plots being used to educate farmers under the AGRA-funded project being led by Dr. Stephen Lyimo from Selian Agricultural Research Institute, Tanzania.

Phosphorus deficiency is becoming increasingly prevalent in cultivated Tanzanian soils, even amongst small-scale farmers. With fertilizer becoming increasing expensive and unaffordable, the ASHC team went to see how farmers in Tanzania are adopting a Minjingu Phosphate, cheaper phosphorus fertilizer with the aim of developing suitable site specific extension materials to popularize its use.

Minjingu Rock Phosphate (MRP), is a mineral found in large quantities in Northern Tanzania. The naturally occurring rock phosphate can be converted into beneficiated (concentrated) rock phosphate (BRP), which is used for improving soil fertility to increase crop yields.

Because of its unique composition and high solubility of its phosphates, MRP has proven to be very beneficial to cash crops; it is increasingly being used in maize intercropped with legumes like common beans, pigeon peas and soybeans, and in rice monocrops.

Advantages of Minjingu phosphate

It is a cheap source of phosphate and also contains other beneficial minerals
It is good for root development
It is soluble in soil water
It is easily absorbed by plant roots
It is applicable to acidic soils
It is natural and environmentally friendly
It is always available and lasts up to five years in soil
It releases locked-in minerals
It stores well
It’s harmless to the soil

NB: Recommended rate of nitrogen fertilizer must be applied at the right time of crop growth as Minjingu phosphate has no nitrogen in it. Minjingu Mazao, a new type of MPR fertilizer that has been on trial has nitrogen and other additional minerals and would be beneficial once released for sale commercially.

The Kenya Agricultural Research Institute (KARI) also supports use of MPR, especially in South-West Kenya, where soils are acidic. For better yields of maize, beans, napier grass, local vegetables, cabbage and kale they recommend soil testing to determine nutrient and acidity levels before applying fertilizers. Soil tests are available in KARI centres at Nairobi, Nakuru, Kisii and Kiambu.

It has been estimated that the mines in Tanzania have 10 million tons of rock phosphate deposit. There is local capacity to process 100,000 tons per annum. Currently the mineral is being exported to South Africa, Zambia, Kenya, Uganda, and Rwanda.

ASHC will be following with interest the AGRA-funded programme and will check up on the progress of some of the other 30,000 farmers being helped to apply this fertilizer to improve their crop yield.

ASHC contact: Grace Omondi – communication specialist

Related information

Minjingu rock phosphate for soil fertility improvement and increased crop yields (Southwest Kenya)

Author: Joseph G. Mureithi