The agriculture and environment are closely interconnected, as agricultural practices significantly impact ecological health, biodiversity, soil quality, and water resources.
The findings of the physical and human research projects were carried out as part of the geography fieldwork. The report is written under the theme of agriculture and environmental change. The field work was carried out between 9th April and 15th April 2017 in Kabwe’s Waya farming block.
The human geography with an aim of investigating smallholder agricultural practices and their effects on soil fertility in Kabwe’s Waya farming block. The second study was on physical geography which had an aim of investigating how smallholder agricultural practices affect soil fertility. The map below shows the exact location of the Waya farming block in Kabwe.
Figure 1.1: Map showing the Location of Kabwe District.
The livelihoods of most of the rural households in Zambia are dependent on land. The smallholder households comprise about 88% of the farming population of Zambia, the smallholder farmers could further be classified into small-scale farmers and medium-scale farmers.
Small-scale farmers cultivate land areas of less than five hectares and comprise about 85% of agricultural households whilst medium-scale farmers cultivate land areas between five and twenty hectares and are about 13% of the agricultural households.
Source: GES 3433 Fieldwork 2017
Both these smallholder households largely use land for agricultural purposes, with an ultimate contribution of 60% to the value of national agricultural output. Smallholder agricultural practices around the globe have adverse effects on soil fertility sustainability, especially in developing countries like Zambia.
These effects have called for a lot of research to be done on smallholder agricultural practices and their effects on soil fertility sustainability. Agriculture and environmental change are closely linked together in one way or the other (Saasa, 2003).
THE SMALLHOLDER AGRICULTURE IN KBWE
Kabwe was once a leading Lead and Zinc mining town. Lead and zinc mining started in 1904 and ended in 1994 when the mines were shut down. As a result of mining in Kabwe, soil fertility has been affected by the lead disposition from the mines. Agriculture has become the major economic activity in Kabwe from the time mining activities declined.
Agriculture is the backbone of Kabwe’s economy. Smallholder farmers depend on agriculture as a source of income and as a means of survival. Kabwe greatly contributes a large percentage towards agricultural yields of crops in Zambia every year. Kabwe is a home for many smallholder farmers (Kabwe District Environmental Report, 2010).
Source: A presentation on Agriculture by senior agricultural officer in kabwe on 10th April, 2017.
Role of the Agricultural Department in Kabwe
In her presentation, she outlined, the activities of the Department of Agriculture in Kabwe the major activities of her department involve playing an advisory role to farmers on sustainable farming practices and conducting training in various farming activities such as farm management, crop production, land husbandry, nutrition, and irrigation.
Farm management involves; training farmers in budgeting and basic farm management, crop production training involves growing and tending of different crops, and crop damage assessment training. Land husbandry training involves conservation agriculture, site plans, and land management.
the nutrition training involves food preservation, value addition, pieces training and meetings and lastly dissemination of irrigation technologies to farmers, irrigation planning and construction training, construction of irrigation facilities
Some of the challenges that are face by DACO include Inadequate resources to carry out planned activities,Inconsistent funding ,Office space does not accommodate all officers ,Depend on one vehicle to run all programs, Inadequate transport for all CEOs, Lack of equipment (GPS, Automatic levels), Lack of Computers and broken down furniture.
Conservation farming
The conservation farming involves the use of sustainable farming practices such as reduced land tillage or minimum tillage in place of maximum tillage, residue retention , which helps to maintain moisture in the soil which is needed for seed germination and also helps to reduces the rate at which top soils is eroded and crop rotation which replenishes the soil by adding nutrient to the soil especially when a cereal is rotated with a legume.
The minimum tillage comes with several advantages ,When it is practiced immediately after harvest, it enables the farmers to plant early; crop residue retention is also an important practice under conservation farming, not burning crop residues after harvest improves organic content and protects crops from termite and other insects.
Farmers are also advised to practice crop rotation, when they plant a cereal in the current year they are advised to plant legumes in the next farming season. Legumes replenish the soils by putting nitrogen back into the soil; conservation farming also calls for intercropping and cover crops as a weed control method.
The Smallholder Agricultural Practices and How They Affect Soil Fertility
Based on the field assessment, observations and interviews in Kabwe’s Waya district, there were a number of activities that were observed and found. The main agricultural practices employed by smallholder farmers in Kabwe include Mono-cropping, intercropping and Crop rotation, this correlates to with the findings and observations in a field assessment report on smallholder farmers (Abiven, 2009).
Mono-cropping is a practice that is widely employed by many smallholder farmers, especially in developing countries around the world . Mono-cropping involves the growing of the same crop year after year on the same field. An example of mono-cropping is a smallholder farmer who has been growing cereals on the same field for the past five year.
Mono-cropping reduces soil fertility because when one crop is grown on the same field year after year , the soil is not replenished ,nutrient levels reduce year after year as they are constantly being used up by the plant leaved the land infertile (Heard,2006).
Intercropping is growing of two or more different crops of different families on the same field, an example of intercropping is a farmer who grows a cereal like maize and a legume like beans together on the same field.
Legumes are unique plan which help to retain certain nutrients in the soil, nitrogen fixation back into in the soil is a more notable advantage that legumes have, which in turn improves nitrogen level in the plant which make the soil fertile.
Source: GES 3433 Fieldwork.
Based on the interviews during the field assessment, crop rotation was also one of the major practices that were employed by smallholder farmers .Crop rotation is the growing of different crops of different families year after year in the same field.
Crop residue retention after harvest was also one among the major smallholder agricultural practices employed by smallholder farmers in Kabwe. Crop residue retention has several advantages which includes addition of organic matter to the soil when crop residues decompose, inhibiting the velocity of running water across fields which in turn reduce sheet erosion and improves infiltration of rainfall. The residue at the same time acts as a physical barrier to the exposure of the soil from the sun. (Shitubanuma, 2015)
How Agricultural Practices and Field Conditions Affect Soil Fertility
Based on the soil samples that were taken to the University of Zambia environmental lab .The figure below shows how nitrogen levels in the soils are affected by the field conditions and agricultural practices
Fig. 1.2 Nitrogen vs. field conditions and agricultural practices
Source: GES 3433 Field Work Results
Form the obtained results of the soil samples it can be observed that fertilizer, legumes and crop rotation which are in red affect nitrogen levels in the soil because they are below the level of significance which is 0.05. Others conditions and practices which are in blue do not affect nitrogen levels in the soils because they are above the level of significance.
Nitrogen levels in the soils are affected by fertilizers, legumes and crop rotation. Legumes retain certain nutrients back into the soil for example legumes improve nitrogen fixation into the soil therefore improving soil fertility. Fertilizer also improves the nitrogen levels in the soils; nitrogen is an important element that is needed by the plant. Crop rotation also improves nitrogen levels in the soil when cereal is rotated with a legume
The figure below shows field conditions and agricultural practices that affect and do not affect phosphorous levels in the soil.
Fig.1.3 Phosphorous vs. field conditions and agricultural practices
Source: GES 3433 Field Work Results
From the obtained results above, it can be observed that intensive tillage and residue burning which are represented by the red colour affect the levels of phosphorous in the soils because they are below the level of significance which is 0.05.
The other conditions and agricultural practices in the blue colour do not affect practices because they are above the level of significance which is 0.05.
The diagram below shows the field conditions and agricultural practices that affect and do not affect levels of organic carbons in the soil.
Fig. Organic carbons vs. field conditions and agricultural practice
Source: GES 3433 Field Work Results
From the obtained results above it can be observed that trees, agroforestry and crop rotation represented by the red colour in the bar graph above affect organic carbon levels in the soils because they are below the level of significance which is 0.05 while the rest of the conditions and agricultural practices do not affect levels of organic content in the soil because they are aboUve the levels of significance which is 0.05.
According to the research findings when the field assessment was undertaken, the soil texture was found to be sandy clay or silt clay in most of the fields were the field assessment took place. In most cases, sandy soils easily lose nutrients during the rainy season due to soil erosion or leaching of nutrients caused by heavy rains leading to soil infertility.
From the observations, the colour of the soil was brown and this implies that the fertility of the soils in Kabwe is on average. In general, brown soils are considered to be a little bit fertile.
According to the results from the soil samples collected in Kabwe which have been shown in the bar graphs above potassium levels in the soils of Kabwe are affected by residue burning only, and the Ph. of the soils in Kabwe is only affected by the rocks and crop residue burning,
Phosphorous is affected by intensive tillage and residue burning. Organic carbon levels in the soil are affected by trees, agroforestry and crop rotation . Phosphorous responds differently and only about 60% of the total phosphorous is lost by non-particulate transfer when fuels are totally consumed, substantial amounts of highly available potassium can be found in the ash and on the soil surface immediately following fire
Crop residue burning on the soil surface reduces the amount of nutrients in the soil and potassium levels in the soil. Burning of crop residue amount and activity of enzymes involved in the circle of mineral elements of the soil is reduced and in some cases on the effects, some chemicals may break dominance inhibiting seed germination.
In conclusion, balancing agricultural productivity with environmental sustainability is crucial for food security and ecological health. Moreover, strategies like sustainable farming, innovation, and responsible water management are vital for mitigating the impact of agriculture on the environment.
