Agricultural Lime: Why you need it.

a black man and a white woman buying farm inputs from a shop

Are you looking to increase crop yield this season? Use of agricultural lime can help you by correcting one of main challenges in Kenya, soil acidity. According to soil testing studies, Acidic soils occupy 13% of Kenya’s land area and 29% of the total land area of sub-Saharan Africa[i]

To increase your farm productivity, you can correct soil acidity by applying agriculture lime, an alkaline fertilizer like ammonium sulfate or use of organic materials. Besides, you can grow crop varieties that are tolerant to acidity. Of all those soil acidity correction, ag lime is the cheapest and most efficient.

Related: How to Test your Soil PH at home-DIY

 Before you can make these decisions, you need to understand more about following parts covered in this article.

Soil acidity in Kenya

Soil AciditypH value
Basic/AlkalineAbove 7.0
Alkaline Near Neutral6.5-7.0
Slightly acidic6.0-6.5
Moderately acidic5.0-6.0
Strongly acidic4.5-5.0
Overly acidicBelow 4.5

The Optimum soil pH for most foods crops is a range of pH 6.0- 7.0. Though a few crops can tolerate slightly acidic soils, further decrease will lower your yields and profits.  At low pH levels, calcium, phosphorus, potassium, magnesium and molybdenum nutrients will become deficient. Alkaline with a PH value of above 7.0, iron, manganese, zinc and phosphorus are deficient hence the need for correction.

Soil acidity is caused by overuse of acidic fertilizers like the Di-Ammonium Phosphate (DAP), heavy rainfall leading to leaching and erosion and finally organic matter decay.

According to a 2018 study[ii], the western, lake and central regions are the worst affected by acidity. These include Kisii, Migori, HomaBay, Siaya, Busia, Bungoma, Kakamega, Kericho, Narok, Uasin Gishu, Elgeyo Marakwet, Baringo, Murang’a, Nyeri, Embu and Meru Counties as shown in the figure below. This affects more than 50% of smallholder farms in Western Kenya region alone.

A map of Kenya showing how Soil Acidity  is spread per county.
Acidic soils occupy around 13% of Kenya’s land area

Soil testing

How can you know if your farm or lawn soil has the correct pH? By soil testing. Soil testing is a quick and accurate method to determine its acidity (pH), availability of plant nutrients like phosphorus, potassium and calcium etc. You can use the soil test results in plant selection, soil preparation, and fertilization. 

 You can do soil analysis yourself at home, use a lawn analysis service provider in your region for a simple dry test or contact an agriculture lab like the UC Davis Analytical Laboratory for an expensive but detailed wet analysis. These will give you results and advice on chemical constituents of soil, plant, water and wastewater, and feed.

To test your soil at home, order a soil testing kit, collect soil samples using a small trowel to make thin slices of soil from random areas of your garden. Each sample should be about a cup. Leave it to dry at room temperature and then place it in a clean plastic container or a Ziploc bag. You should label the sample and give it a date.  Use your re-usable soil testers you can buy online for quick results. You can mail this for further analysis.

Use of lime in agriculture.

Can dolomite use in agriculture give you more crop yields? The simple answer is yes. The agricultural lime is a soil additive or a corrective input to raise soil PH[iii]. It made from pulverized limestone or chalk, the same raw material used in making building cement.

As a farmer you can use the Agricultural lime in form of magnesium or calcium forms and several states: oxides, hydroxide, silicate or carbonate. The most popular ones in Kenya are main types of agricultural limes in the Kenyan market are the calcitic lime – calcium carbonate (CaCO3) and dolomitic lime (CaCO3.MgCO3 or CaMg (CO3)2.

Benefits of agriculture lime

Use of lime will raise your soil pH. It will improve your crop yields by assisting plants to uptake more nitrogen, phosphorus, magnesium and potassium in acidic soils. “I applied lime in my farm where I grow Rhodes Grass; I was able to realize increased yields from 90 bales to 170 bales and I realized increased tomato yields from 70 to 90 crates” –Farmer from North Rift

 Other benefits according to a 2021 KMT study are:-

  • Promote better nitrogen fixation by legumes.
  • Reduce toxicities in the soil (Reduces Aluminium (Al) and Manganese (Mn) toxicities).
  • Enhance the effectiveness of some herbicides and fertilizers.
  • Improve the soil ability to store water.
  • Permits improved water penetration for acidic soils.
  • Promotes crops root development.

The net effect is that you will improve farm yields and profits. Besides as a farmer, you will reduce cost of production which will translate to affordable food for consumers. To note, though investing in agriculture lime for your farm looks like an additional cost, the additional yields will offset this cost for you. Some limes are low release and may enjoy benefits for 2 to 3 years after application.

Types of agricultural lime

An inforgraphic showing benefits of using agricultural lime

The agricultural lime in bulk is expensive. To make it available for small scale farmers in the region, it is processed and marketed in the following forms:

  • Lime Powder – crushed limestone into powder/chalk form and packed in 50kg bags.
  • Granulated form – crushed/powder lime is processed into granular form for easier field application.
  • Pelletized agricultural lime-Limestone is finely ground pulverized limestone for sale with an organic binder to form a pellet. It the easiest to handle and use, odor free and has long storage.
  • Liquid agLime – The lime is suspended in liquid form for instant activity in the soil and can be applied on already growing fields.

You can apply ag lime by broadcasting or micro-dosing. You can combine it with fertilizers and seeds or do it separately. The suggested farm lime application rate is four tons/ha or 1.6 tons/acre. For microdosing, its more efficient and can be as low as 0.5 tons/acre.

Where to buy Agricultural Lime

Are you looking for agricultural lime for sale near your area? There are More than 20 different agricultural lime products in the region. They are available from at least eight local companies in Kenya. The major ones are the Homa Lime Company and Athi River Mining (ARM)-Mavuno Fertilizers Company.

Read Next: Where to buy fertilizers in Kenya

You can buy pelletized, liquid, granulated and powder lime from leading online farm stores like the Home depot, Tractor Supply and Amazon.

 Cost of agriculture lime

The national demand is approximately 187,000 MT annually. On average, powder lime costs KES 6,000 per MT at ex-factory prices and KES 8,000 for the retail prices. In your nearest agro-dealer, you can buy a 50kgs bag of powder lime at Kshs. 350 per (or Kshs.7 per kg). Demand is high among the coffee, maize, and sugarcane farmers in Western, Rift Valley, Lake region and and Central Kenya regions of Mt Kenya and Aberdares.

Read More about agriculture lime Market


S.K.

S.K is the founder and senior agribusiness development consultant at Agcenture. He can be reached at info@agcenture.com

You may also like...

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.