By Fergus Robley, the General Manager of FMD, the Massey Ferguson distributor for East Africa
As a major step towards the food security and nutrition pillar of the government objectives, improved yields of cereals can be achieved quickly by adopting best farming practices. These include avoidance of mono crop cultivation and rotating crops, using quality seeds, appropriate fertilizers for soil conditioning, mechanization, minimum tillage and leaving land fallow from time to time.
Irrigation is being touted as an answer to the erratic rainfall caused by climate change, but establishing large scale irrigation involves heavy expenditure. In addition to the cost of piping, irrigation systems and pumps, a constant large supply of water is vital for success. Borehole water in many areas of Kenya can be unsuitable for irrigation and can also have an irreversible detrimental long term effect on our soils.
Maize is the favoured crop among many farmers who have been growing this year after year using the same farming regime. This has depleted the nutrients in the soil and has caused an annual decline in yields.
By rotating maize with other crops and carrying out soil analysis to introduce the most appropriate fertilizers and trace elements farmers will achieve better harvests and greater profitability.
Mechanization has been recognized as the way forward for productive farming, but in most cases is beyond the reach of small land owners. In fact the benefits of mechanization can be brought to small scale farmers by contractors, or groups of farmers joining hands to purchase tractors, ploughs, planters and spray equipment.
The most promising boost in cereal output can be achieved by adopting minimum tillage (also known as conservation agriculture). Minimum tillage has been used in Brazil for years in areas with less rain than Laikipia to produce good harvests whilst preserving soil structure and moisture. This holds the prospect of expanding cultivating cereals to comparatively dry areas like Kitui, Makueni, Isiolo and Marsabit.
The use of disc ploughs to invert the soil causes moisture loss and following up with disc harrows give further moisture loss along with soil degradation. The end result is a dry seed bed with poor soil structure causing limited crop yields.
In contrast minimum tillage as a method of best farming practice to prepare land for cultivation with a chisel plough, or a deep sub-soiler preserves moisture in the soil and allows for an economical one pass for land preparation. This corrects the effects of regular use of disc ploughs and harrows over a period of years which causes hard pans and does not protect the soils for the future.
Preparing soil with a chisel plough, or deep subsoiler protects moisture within the seed bed and preserves surface trash whilst providing the necessary aeration and soil shattering under the surface.
This retention of valuable moisture is comparable to that of a forest floor with fallen leaves on the surface. This provides similar preservation of moisture by acting as an umbrella for the soil and contributes to the organic matter which assists with moisture retention qualities that the preserved carbon gives.
One pass with a crumbler roller on the back of a subsoiler leaves the land ready for planting. Clearing the necessary weeds for planting can be achieved by using a cultivator (mechanical method), or crop sprayer (chemical method) prior to planting. The latter usually giving better results.
While minimum tillage cultivation is of great importance in dry rainfall areas it is very effective for most farmers anywhere in Kenya. By preserving soil moisture, farmers in areas like Kampi Ya Moto and Laikipia which were previously thought to be marginal for arable crops are achieving good results.
The equipment needed for minimum tillage consists of a good 4WD tractor, a subsoiler, a sprayer in sound working condition and a planter that is set up correctly to give the necessary plant population. Calibration of sprayers and planters are key for successful best farming practices.
The best land preparation is achieved using a deep tine to penetrate the soil to a depth of 18 inches (45cm) to overcome the mechanical hard pan that usually occurs at eight to ten inches below the surface which results from years of disc ploughing and harrowing. The addition of using a subsoiler with a crumbler roller also provides a level and favorable seed bed for planting.
To demonstrate the improved yields from minimum tillage, trials are being held on three adjacent plots in the Njoro area to show the output from conventional cultivation, minimum tillage and planting without tillage. The results will be available at the Panafrican Equipment FMD Field Day.
Farmers interested in attending the Field Day can receive invitations by phoning Lucy Mukuru on 0722 205 538.