PREAMBLE

Poor farm productivity results from many on-farm practices that are considered within the farmer’s reach to modify so as to improve yields. While some are capital intensive some require a rearrangement of crops so that they complement each other in the utilization of environmental resources, instead of being antagonistic or highly competitive. There are some environmental factors, which if properly harnessed can improve the productivity of the crops. To begin to upscale these practices one must realize that current practices have evolved over centuries, have sustained the farmers albeit at subsistence level, and thus the variations have to be around his current practice but in a better sustainable manner.  

Sustainable agriculture:

• Sustains the economic viability of farm operations
• Satisfies human food, fiber and energy needs
• Maintains or enhances the resource base upon which it depends by emphasizing soil conservation, nutrient recycling, biological based-pest management and biodiversity
• Takes advantage of the knowledge and skills of farmers
• Is durable and resilient to disturbance, pest outbreaks and market variability
• Makes the most efficient use of nonrenewable resources and on-farm resources
• Integrates, where appropriate, natural biological cycle and pest control tools with production practices.

Soil Productivity:

Poor farm productivity results from long usage of available land without adequate soil maintenance procedure. The continuous removal of harvested crops without adequate replacement of the removed nutrients is soil mining which results in the continual reduction in yields. If this process continues without any intervention over a period of time, the soil becomes degraded and unable to support any meaningful yields. The usual method of intervention was the fallow system; but with the population growth, the practice was no longer sustainable as more land was taken up for housing, industries, and other development infrastructures.

Also the improper/inadequate use of chemical fertilizer have not improved the situation. Some of these fertilizers are crop specific in the rate applied and could thus be detrimental to a companion crop. Thus the full advantage of existing knowledge could not be utilized, and the cultivation of monoculture was often advocated. If we are to take advantage of the farmers’ skills and knowledge, we need a rethink of strategies that will incorporate the farmers dreams: to adequately produce food and cash crops in quantities that will reduce poverty and promote growth.

Soil Fertility:

Land exposure can lead to soil erosion, the loss of the top soil rich in nutrients and together with soil mining lead to soil degradation. To arrest or ameliorate soil degradation processes, land coverage and the proper fertilization of the soil is advocated. Tropical soils are largely oxisols – poor in ion exchange capacity, low in potential to absorb nutrients, resulting in the washing of mineral fertilizers applied. Therefore, the upscaling of agricultural production cannot be undertaken with only mineral fertilization in mind as only healthy soils will be able to produce the desired result of improving and sustaining production among the smallholders in the tropics. In such circumstances, organic matter takes on a vital role because it can retain nutrients and convey them to the plant. Rehabilitating degraded soils requires substantial investment, and the amount of manures required to improve and sustain productivity are beyond smallholders. However, some methods that can be used to improve the soil’s fertility include the following:

• Crop Rotation
• Cover Cropping
• Composting
• Green Manuring
• Farm Yard Manure
• Improved Fallow System
• Fertilizer Tree System

Cover cropping can be a problem because of the long dry season in the savannas, but modifications are possible with biennials or triennials in the improved fallow system (IFS).

Green manures are restricted to areas with long growing season, but a modified form has been developed (Odion, 2007) where legume companion crops are either clipped or thinned and the fodder used as green manure.

Fertilizer tree system (FTS) may also be restricted to wetter regions, but like in IFS, drought resistant biennials/triennials can be used in an alley cropping system to reduce the exposure of land and thus erosion.

Farm yard manures can either be purchased and applied to the farm if the farmer has no animals or the farmer can agree with herders to corral their animals on his farm. The animals will feed on the crop residues in exchange for the waste they will leave behind.

Improved Fallow System (IFS) is when fallow areas are deliberately cultivated with biennial/triennial leguminous herbs for improved soil fertility so that the soil can regenerate faster. Such legumes should be of economic values so that the soil can be protected from fires and grazing during the dry season.

Composting is an aspect of fertility highly desired to return nutrients back to the farm but is neglected at the moment. Most farm produce taken to the market ends up in waste dumps for landfill. This gives rise to production of methane: a greenhouse gas, partly responsible for global warming. The process is part of the soil mining of farms responsible for soil degradation. In the same way, rumen content from slaughtered animals in abattoirs are left in waste dumps to pollute the environment and also produce methane. However, if market wastes from farms are mixed with rumen content from the abattoir we can produce compost from them (Odion, 2018), that can be returned to the farm or/and grazing areas. This will not only reduce greenhouse gas emission but also sequester carbon into the soil, enriching it further. For the savannas where most animals are raised the process is a win-win situation as it will reduce the cost of external inputs while reducing the degradation of farm and grazing lands. The process mimics vermicomposting (the use of earthworms to process crop residue), and can be undertaken wherever animals are slaughtered and at different levels – small, medium or large.       

The above measures are for the mixed cropping culture of the smallholder and so has to be managed properly to foster quick land coverage through intensification of crop production. Thus some knowledge of crop arrangement in mixture will be desirable.

Crop Protection:

Protecting the crops from planting through vegetative and reproductive growth phases will be highly desirable for optimum performance of the crop and yields.

Weed Control:

The use of chemical should be discouraged thus hoe weeding, mechanical weeding or the use of biological weed control should be encouraged and/or researched.