S/N | Test result | Situation indicated | Possible causes |
1 | Low ground cover | Ground plants absent or plant growth is poor | Unsuitable plant type(s), soil compaction, soil erosion, shading, overstocking (animals eating most of the plant residues) |
2 | Low variety of soil fauna | Lack of food for fauna, poor soil structure, presence of harmful (agro)chemicals | Sparse litter, low soil organic matter, lack of soil spaces and channels, frequency or intensity of tillage has been excessive, mortality from recent use of insecticides or regular use of cumulative chemical(s) such as copper fungicides |
3 | Low earthworm count | pH unfavorable, poor food supply, lack of soil spaces, predators or parasites present, presence of harmful chemical | Soil pH naturally low, sparse litter and/or ground cover (and roots), low organic matter content, loss of topsoil, soil compaction, poor structure, predators (such as flatworms) and parasites (e.g. parasitic flies, mortality from recent use of insecticides or regular use of cumulative chemical(s) such as copper fungicides |
4 | Low probe penetrability | Soil is generally hard at the surface only, hard layer at greater depth | Low organic matter content, compacted by traffic or livestock due to overstocking) especially if soil is wet at the time, compacted by heavy vehicles or “hard pan” formed by soil inverting cultivators |
5 | Slow water infiltration | High proportion of clay particles and lack of spaces, channels or burrows in soil | Naturally high clay content of soil type, possible loss of topsoil through erosion, soil compaction, poor soil structure, lack of earthworms, surface crusting |
6 | Poor root development | Hard soil lacking spaces, poor plant nutrition, root disease or attack | Loss of topsoil, poor soil structure, soil compaction, soil pH not suitable for crop, lack of major or minor nutrients, presence of soil-borne plant pathogens, root-feeding nematodes or root-feeding insects |
7 | Poor soil structure | Powdery soil, few crumbs, excessive clods | Lack of soil-binding substances and processes, low soil organic matter content (sparse ground cover), few worms, topsoil loss, soil compaction, “puddling” of wet soil by livestock, excessive cultivation |
8 | Low aggregate stability (leading to high slaking of soil aggregates) | Soil particles disperse when wet | Topsoil loss (0 - 10 cm), compaction, low organic matter, excess tillage down to 20 cm, poor mixing of soil by soil animals, acidic soil conditions |
9 | Poor leaf color | Unthrifty (poorly-growing) plant | Deficiency or unavailability of one or more essential nutrients (e.g. P, N, K, Ca, etc.), (can be confirmed by soil or leaf analysis), presence of some plant diseases, water logging |