Soil provides crucial nutrients and water for the growth of canola, which is one of the most essential economic crops for prairie province in Canada. Therefore, effective and efficient methods are required to modify soil properties to improve crop development. This study systematically analyzed the combined effects of tillage operation and crop residue management on soil features. Thus, the relationship between soil properties and crop yield was also evaluated. More specifically, Aftermarket chopper treatment could cause rela tively higher soil moisture and temperature, while the Original Equipment Manufacturer (OEM) treatment could also result in dramatically higher soil organic matter (SOM) loss than Aftermarket treatment. The significantly more soil water and slightly higher soil temperature created by Aftermarket treatment was beneficial for crop yield. Although OEM treatment could cause more SOM loss, the final crop yield through this method was still lower than that using Aftermarket treatment, implying that the influence of SOM loss on crop growth remained contestable. Meanwhile, Fourier-transform infrared (FTIR) spectra showed the peaks of amides and carboxylic acids was declined during the growth of canola, which indicated that these organic contents played an essential role in the crop development. Finally, the Aftermarket * Harrow treatment was more suitable for canola cultivation, with largest amount of crop harvest and short loss of soil organic contents in the meantime.

The demand for milk rises dramatically due to the increased global population without damaging the standard of living. As a result, the scale of the dairy industry in the world is growing rapidly. Consequently, a concomitant problem that needs to be faced is the environmental impact of the by-products produced during the operation of the dairy farm. Among the substances produced in dairy farms, the most harmful pollutant to the environment is nitrogen (N). In addition, the N pollution from dairy farms is significant and N has a great danger to human health and society. This study provides a systematic review on how to alleviate N pollution from dairy cows during milk production and the removal of ammonia and nitrate from dairy wastewater via biochar adsorption. First, from a physiological perspective, the metabolic pathways of amino acids and ammonia in the rumen, portal-drained viscera, liver, and mammary gland of dairy cows are elaborated, as well as the measures to improve N utilization. In the second part, the progress of research on the removal of ammonia and nitrate by biochar adsorption and the involved mechanisms are summarized. Modified biochar has a significant improvement in nitrate removal due to weakening the repulsive effect of ions. Based on the review of this paper, it can provide relevant theoretical support for future studies on N pollution mitigation from dairy farms.