Small-scale conservation tillage - Ripping of soil using oxen-drawn implements, to improve water storage capacity and cropland productivity on small-scale farms in Kenia

Summary

The form of conservation agriculture described in this case study involves the use of ox-drawn ploughs, modified to rip the soil. Ripping is performed in one
pass, to a depth of 10 cm, after harvest.
The aim of ripping is to increase water infiltration and reduce runoff. In contrast to conventional tillage, the soil is not inverted, thus leaving a certain amount
of crop residue on the surface. As a result, the soil is less exposed and not so vulnerable to the impact of splash and sheet erosion, and water loss through
evaporation and runoff. In addition, there are savings in terms of energy used for cultivation. In well-ripped fields, rainfall from storms at the onset of the growing
season is stored within the rooting zone, and is therefore available to the crop during subsequent drought spells. Ripping the soil during the dry season combined with a mulch cover reduces germination of weeds, leaving fields ready for planting. Yields from small-scale conservation tillage can be more than 60% higher than under conventional ploughing.

Description

Ripping of soil using oxen-drawn implements, to improve water storage capacity and cropland productivity on small-scale farms. Laikipia District in Kenya is characterised by a semi-arid climate, high altitude and rolling terrain. Most of the soil and water loss occurs during a few heavy storms at the beginning of each growing season. More than 90% of families have under two hectares of land, and few have alternative sources of income.

The form of conservation agriculture described in this case study involves the use of ox-drawn ploughs, modified to rip the soil. Ripping is performed in one pass, to a depth of 10 cm, after harvest. Spacing between the rip lines is 30 cm – in the case of wheat. Deep ripping (subsoiling) with the same implement is done, when necessary, to break a plough pan and reaches depths of up to 30 cm. An adaptation to the ordinary plough beam (the common mouldboard ‘Victory’ plough) makes adjustment to different depths possible and turns it into a ripper for surface and deeper ripping.

The aim of ripping is to increase water infiltration and reduce runoff. In contrast to conventional tillage, the soil is not inverted, thus leaving a certain amount of crop residue on the surface. As a result, the soil is less exposed and not so vulnerable to the impact of splash and sheet erosion, and water loss through evaporation and runoff. In addition, there are savings in terms of energy used for cultivation. In well-ripped fields, rainfall from storms at the onset of the growing season is stored within the rooting zone, and is therefore available to the crop during subsequent drought spells. Ripping the soil during the dry season combined with a mulch cover reduces germination of weeds, leaving fields ready for planting. In case of stubborn weeds, pre-emergence herbicides are used for control.

Yields from small-scale conservation tillage can be more than 60% higher than under conventional ploughing. An additional important benefit is that crops mature sooner in conservation agriculture, because they can be planted earlier: under inversion tillage the farmer has to wait for the soil to become moist before ploughing. Earlier crop maturity means access to markets when prices are still high.

There are various supportive technologies in use which can improve the effectiveness of the ripping. These include: (1) use of compost/manure to improve soil structure for better water storage; (2) use of a cover crop (eg Mucuna pruriens) planted at the end of the season to prevent erosion, control weeds and improve soil quality; (3) agroforestry: principally Grevillea robusta planted on the field boundaries (see also ‘Grevillea agroforestry system’).

The joint effects of the different advantages that this type of tillage has will help improving the resilience of livelihoods of Lakipia against natural hazards. The better infiltration will help better resistence against intense rainfall and drought. The improvement in crop yield will affect positively the nutritional status of the farmers and allowing them to diversify and increase their income.

ClassificationLand use problems- loss of rainwater through runoff and direct evaporation from soil surface- runoff causing surface erosion- fertility decline due to erosion and nutrient mining

Further reading

Countries

Kenya

Created date

Tue, 12/06/2012 - 10:14

Attached files

Source(s)

WOCAT (World Overview of Conservation Approaches and Technologies) network

WOCAT (World Overview of Conservation Approaches and Technologies) is a global network of Soil and Water Conservation (SWC) specialists, contributing to sustainable land management (SLM).

WOCAT’s goal is to prevent and reduce land degradation through SLM technologies and their implementation approaches. The network provides tools that allow SLM specialists to identify fields and needs of action, share their valuable knowledge in land management, that assist them in their search for appropriate SLM technologies and approaches, and that support them in making decisions in the field and at the planning level and in up-scaling identified best practices.

WOCAT was initiated nearly 20 years ago by a concerned group of soil and water conservation professionals who identified the need to counter the prevailing pessimistic view of land degradation. Today WOCAT is a thriving knowledge management hub for Sustainable Land Management (SLM). It has carried out its activities with more than 50 national and regional groups, documenting more than 470 SLM technologies and 230 SLM approaches with training provided to over 500 practitioners in the application of the methods and tools. This portfolio of experience and records makes WOCAT the premier platform of information on land resources and their use (including databases for data storage and retrieval), with direct application to knowledge of soil and water conservation and outstanding potential to help deliver current agendas in sustainable land management, climate change adaptation and climate resilience planning.

WOCAT is a consortium of national and international institutions, led by a core Management Group of CDE, FAO and ISRIC[1]. The Secretariat for WOCAT at the Centre for Development and Environment, Bern, has extensive experience in database and knowledge management for all land-based investments.

[1] CDE: Centre for Development and Environment, University of Bern, Switzerland; FAO: Food and Agricultural Organization, Rome, Italy; ISRIC: World Soil Information Wageningen, The Netherlands

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