Soil improvement should start with the problem that needs addressing. Compacted soil, poor drainage, unsuitable pH and salt-affected soil are different problems.
Choose indicators according to the question
USDA NRCS uses physical, chemical and biological groups of indicators to assess soil. This framework helps avoid treating a single indicator as representative of every property.
Growers should record current conditions, input history and sampling locations. If analysis is needed, agree on the method, depth and timing so that later measurements have a basis for comparison.
Manage the entire system, rather than only adding fertilizer
NRCS sets out principles of maintaining living roots, reducing disturbance, keeping soil covered and increasing diversity. Their application needs to suit crops and local conditions.
From these principles, individual monitoring plans can be developed for cover, crop rotation and soil practices. Vermicompost is an input that may be considered within the plan; it does not replace assessing the cause of the problem.
Water sources also need checking
Irrigation needs should not be addressed by using wastewater of unknown quality. When the water source changes, assess information relevant to the intended use before introducing it into the growing system.
For soil with pH or salinity problems or suspected contamination, this article does not provide a general treatment rate. Suitable results and professional advice are needed for the specific situation.
Record results over time
Prepare a table of activities, inputs, weather conditions and measurement results. If comparing two areas, describe differences that could affect the results. Do not promise that all soil will recover within a fixed period; only conclude changes within the scope monitored.
Read more: Water-holding soil with good structure: assessing the effects of vermicompost; Vermicompost and soil carbon: distinguishing concentration, stocks and emissions.