A new publication in Food Energy and Security demonstrates how farm management affects food productivity and soil health at the Tulloch LTE.
Work conducted at the Tulloch long term agroecological experiment has shed new light on the interactions between farm management, food production and soil health. Legume supported (organic) rotations with and without grazing livestock has allowed researchers to consider the environmental implications of changing diets. Livestock produce food from otherwise inedible crops and their manure is a valuable soil conditioner. But plant-based diets are becoming more widespread due to perceived environmental benefits.
The team at SRUC calculated the food value of yields from each of the rotations, and used farm management records to assess the balance of nitrogen, phosphorus, and potassium in each system.
Legume-supported rotations without livestock produced more protein, starch and sugar per unit area than those with livestock which produced more fat. The manure applied to the rotations with livestock was a key contributor to nutrient balances; the rotation without livestock was found to lose nutrients through time. Looking at the health of the underlying soil, they used the agroecological systems at Tulloch to identify which soil health tests were linked with higher crop yields. Tests chosen included field assessments (earthworm counts and visual evaluation of soil structure scores) together with laboratory analysis of soil structure, chemistry and biology. Results highlighted the impact of farm management on soil biology with the plots with a longer ley duration, higher soil organic matter, and higher potentially mineralisable nitrogen linked to higher yields.
