An Enhanced Soil Health Card Method for Soil Quality Assessment towards Improving Land Management Practices

Abstract

Soil quality is the capacity of a specific kind of soil to function within natural or managed ecosystem boundaries to sustain plant and animal productivity; maintain or enhance water and air quality and support human health and habitation. Soil function describes what the soil does. The terms soil quality, soil health, and soil condition are all interchangeable. Soils vary naturally in their capacity to function; therefore, quality is specific to each kind of soil. This concept encompasses two distinct but interconnected parts: inherent quality and dynamic quality. Characteristics, such as texture, mineralogy, etc., are innate soil properties determined by the factors of soil formation climate, topography, vegetation, parent material, and time. Collectively, these properties determine the inherent quality of a soil. They help compare one soil to another and evaluate soils for specific uses. For example, all else being equal, a loamy soil will have a higher water holding capacity than a sandy soil; thus, the loamy soil has a higher inherent soil quality. This concept is generally referred to as soil capability. Map unit descriptions in soil survey reports are based on differences in the inherent properties of soils. More recently, soil quality has come to refer to the dynamic quality of soils, defined as the changing nature of soil properties resulting from human use and management. Some management practices, such as the use of cover crops, increase organic matter can have a positive effect on soil quality. Other management practices, such as tilling the soil when wet, adversely affect soil quality by increasing compaction. In this research, soil quality refers to the dynamic quality of soil those properties that are affected by management. Soil quality evaluation is a tool to assess management-induced changes in the soil and to link existing resource concerns to environmentally sound land management practices.Soil quality assessments are thus used to evaluate the effects of management on the health of the soil.

Having such concept into consideration, the Natural Resources Conservation Service in USDA (NRCS, 2001) has produced guidelines for soil quality assessment in order to monitor, manage and prevent soils from incidence of deghradation hazards. Within this context, NRCS has developed a health card intended to be utilized in collaboration with the farmers, scientists, agriculture research centers and extension especialists. This health card is a collection of procedures that assess changes in in soil qualities through identifying relevant soil indicators that are affected by different aspects of field mannagement. These indicators can be of physical, chemical or biological soil properties and/ or crop conditions related to soil characteristics.

The aim of this study is to present procedures to provide information for performing soil quality assessments at Khartoum State, Sudan. Khartoum state was chosen to apply the procedure for designing ,adapting and producing soil health card based on accumulated information by farmers and researchers on soil properties, their use and management at different parts of Khartoum State. This will enable assessing the impact management on soil qualities and to identify and diagnoses reason problems in addition to monitor hazards caused by mismanagement .The complete procedures of the health card could be used for informal soil quality assessment but the included rating chart could be used for quick assessment. The soil health card is composed of four parts in one leaflet. The first part shows the farmer important of soil health and quality and how to maintain it. The second part contains indicator that found in the area to advance soil management. The third part contains the results of laboratory soil analysis. The fourth part shows how to take the field soil sample and some of the observations on management practices (tillage, fertilizer, irrigation, crop system) and eventually allows space for remarks and recommendation for soil conservation. The health card is intended to be used by farm managers and knowledgeable farmers with some support from local extension officers. Other States in Sudan could modify Khartoum health card for soil quality assessment to suit their soil conditions that might have different indicators.