Scientific research

Increasing fertility of alkaline and solonets soils

Author: Knowledge Management in CACILM Phase II, ICARDA.

Definition of technology:

The technology is based on the use of phosphogypsum to improve the physical-chemical soil properties

Brief summary of technology:

This technology is found effective in the southern regions of Kazakhstan, where irrigated lands are characterized as alkaline and solonets. Currently, there are many known methods of chemical amelioration of alkaline soils by adding materials containing calcium, which displaces exchangeable magnesium and sodium from the soil-absorbing complex and replaces it with calcium.

In Southern Kazakhstan, phosphogypsum is the most affordable and cheap chemical ameliorant. It belongs to acidic ameliorants and is therefore better soluble in alkaline medium and provides a substantial improvement of the physico-chemical properties of alkaline and solonets soils: it increases calcium contents of the absorbed bases, acts as a bio-chemical barrier (coagulator of salts), increases the rate of water absorption by 30-35%, accelerates plant growth and development, improve the water supply to plants and reduces water consumption per unit of production.

Soil fertility and productivity of crops increase twice. Efficiency of the ameliorants depends on the application methods and timing. Currently, surface application of phosphogypsum during plowing until massive precipitation or snow in autumn-winter is the most profitable, because under this method the cost of the acquisition and application of phosphogypsum is repaid in 1-2 years. The use of advanced technology of phosphogypsum application ensures sustainable development of irrigated agriculture, reduction of the cost of chemical amelioration to 30% and increase of the farm incomes to 50%.

Figure 1. Phosphogypsum application.

Figure 2. Plant conditions on alkaline soils.

Figure 3. General view of the field with applied phosphogypsum.

Location: Jambil and South Kazakhstan provinces.

Area of technology application: 10-100 ha.

Stage of intervention: alleviation / reduction of land degradation.

Main land use issues and the main causes of land degradation:

Intensive salinization, alkalinization and solonets of soil due to natural factors and inappropriate agronomic and agrotechnical practices, leading to a deterioration of water-salt and nutrient balances, reduction of soil fertility and crop yields.

Main technical features of technology:

Displacement of harmful for plants magnesium and sodium elements from the absorbed bases and replacing them with calcium, improving soil structure, water and salt and nutrient regime.

Type of land use Conservation measures

Irrigated arable land.

Cultivation of annual crops - Во(Ca).

Agronomic measures:

A5: Application of ameliorants.

Environment

Habitat Anthropogenic environment

Average annual rainfall: 250-500 mm.

Altitude (meter above sea level): 500-1000 m.

Landscape: Plateau/flat, valleys.

Slope (%): 0-2%.

Soil fertility: low, average.

Humus content in arable horizon: <1%; 1-3%.

Natural soil drainage/infiltration: average, poor.

Size of land area (ha): 50-100 ha.

Landholder: cooperatives, medium land users.

Land ownership: land lease.

Water use rights: through water user associations (WUA), and state manage the irrigation systems on relevant payment.

Market orientation: mixed farming (subsistence and commercial).

Assessment

Impact of technology

Main advantages:

- increase of crop yield (small 5-20% to 1.8 t/ha, later 2.8-3.3 t/ha);

- reduction of demand for irrigation water (5-20%) to 4500 m3/ha after 3200 m3);

- reduction of costs for inputs (average 20-50% for fertilizers and seeds);

- increasing farm incomes (average 20-50% due to yield up to 500 USD/ha);

- reduction of workload (average 20-50% reduction in labor costs).

Main disadvantages:

- high costs of transportation of phosphogypsum from factory to irrigated land.

Acceptance/adoption of technology: 5 land user households implemented the technology with the help of external financial support in Zhambyl and South Kazakhstan provinces. There is a tendency of spontaneous adoption of technology.

Reference(s):

1. Introduction of technology to improve fertility of solonets irrigated soils by adding phosphogypsum // Final Report. - Taraz, 2008. -107 p.

2. Recommendations for improving the technology of the use of chemical ameliorants to enhance crop yields in the merged soils (alkaline, alkaline). - Taraz, 2007. - 22 p.

Name of person(s) collected this description: Bekbaev R.K., Head of department of amelioration and ecology of the irrigated areas, KazNII of water resources management.

Address: 12, K.Koygeldy st., 800003, Taraz.

Теl.: +7 726 2426836, Моb.: +7 775 1009995,

Е-mail: Bekbayev_55@mail.ru

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