Reducing topsoil depth decreases the yield and nutrient uptake of maize and soybean grown in a glacial till

Abstract

Soil erosion decreases topsoil depth on hill slopes and increases depth in depositional areas, and hence impacts soil fertility and crop productivity in agricultural systems. However, it is not clearly elucidated how different crop species adapt to soil erosion regarding root function, nutrient uptake, and rhizosphere biochemical properties, which is pivotal to cropping strategy. We established three simulated erosion severities with topsoil depths of 10, 20, and 30 cm on a Mollisol farmland under a maizesoybean rotation system with no-tillage (zero-tillage). After three consecutive years of field experiment, the decrease in topsoil thickness from 30 to 10 cm resulted in 9-22% decrease in maize yield but no impact on soybean yield. Compared to the 30-and 20-cm topsoil thickness, the 10-cm topsoil significantly lowered root and shoot biomass of maize at the jointing (V7) and milk stages (R3) and of soybean at the mid-seed filling stage (R6). Compared to the 30-cm topsoil treatment, the 10-cm topsoil decreased available N and P in soil by 42 and 36% under maize, and by 25 and 19% under soybean, respectively, while the shallow topsoil also decreased ratios of N, P, and K content to root length with the decreases being less for maize than soybean. Compared to the 30-cm topsoil depth, the 10-and 20-cm topsoil significantly increased the activities of urease, phosphatase, and invertase in maize rhizosphere soil, but not in soybean rhizosphere soil except for the activity of urease in 10-cm topsoil. These results indicated that maize was more sensitive to thinning of topsoil than soybean due to the reduced soil nutrient availability and its capability to extract nutrients from the soil. The greater stimulation of nutrient mineralization processes in soil did not alleviate the nutrient constraint to maize yield under shallow topsoil conditions. Thus, it is increasingly important to develop fertilization strategy to maintain nutrient supply for maize rather than soybean when these crops are grown in the shallow topsoil.

Depth‐dependent responses of the soil bacterial community under vegetation restoration in soil erosion areas of southern China

“…In this study, vegetation restoration significantly improved the pH and nutrient content in soil erosion areas and enhanced the soil structure. First, the recovery of aboveground vegetation communities slowed the impact of raindrops, while the belowground root systems of plants helped stabilize soil particles, collectively reducing the risk of soil erosion (Guo et al, 2021). Additionally, plant litter forms a protective layer on the soil surface, reducing soil evaporation and water loss (Zhou et al, 2021).…”

Integrating Crop Modeling and Machine Learning for the Improved Prediction of Dryland Wheat Yield

“…Similarly, Dai et al [82] emphasized the importance of soil factors in accurately predicting crop yields in a study conducted in 2011. Recent studies, such as the work by Guo et al [83] in 2021 and Jiang et al [84] in the same year, further explore how soil properties and meteorological conditions impact crop yields. Results similar to those proposed by Zou et al [40], which suggested capturing additional variability in predicting county-level corn yields in China using data from simulated crop model outputs combined with basic learners (RF), were obtained (R 2 ≥ 0.9, RMSE < 750 kg/ha, and MAE < 500 kg/ha).…”

County-scale crop yield prediction by integrating crop simulation with machine learning models

“…Leuthold et al (2022) applied a linear regression model to identify the correlation between topography and corn (crop) yield, where the relationship varied with precipitation. Some recent studies focused on understanding the impact of soil properties and meteorology on crop yield (Guo et al, 2021;Jiang et al, 2021). Weather, soil, and management information were fed as input to the ML models and focused on interpreting the model performance with different weather and soil conditions.…”