Paul R. Poulton

TL;DR: The results suggest enhanced P losses through subsurface runoff on heavy soils, once a certain plow layer concentration of Olsen-P is exceeded as mentioned in this paper, which is the change point.

TL;DR: The results from two long-term experiments demonstrate that manuring significantly raises δ 15 N in cereal grain and chaff, and of charring on these cereal values, and indicates that human diets with a major component of such grain would conventionally be interpreted as indicating a largely animal-based diet or a mixed plant/animal diet.

TL;DR: In this paper, the authors studied the effect of soil fertility, crop, manuring, and management on changes in soil organic matter under temperate climatic conditions and found that the amount of organic matter in soil depends on the input of organic material, its rate of decomposition, the rate at which existing soil organic material is mineralized, soil texture, and climate.

TL;DR: Evaluated changes in the mineral concentration of wheat using a robust approach showed that both increasing yield and harvest index were highly significant factors that explained the downward trend in grain mineral concentration.

TL;DR: In this article, a model for the turnover of organic carbon in non-waterlogged soils, RothC-26.3, was fitted to measurements of carbon from 18 different experimental treatments on 6 long-term experimental sites in Germany, England, the USA, the Czech Republic and Australia.