Novel Organic Amendments to Enhance Nutrient Cycling and Organic Matter in Problem Soils

这项拟议的研究评估了在萨斯喀彻温省受化学、物理和生物挑战的盐分影响土壤中添加新型有机改良剂的影响，包括生物炭、腐殖质(莱昂纳德特)和堆肥有机肥。计划中的研究将解决有关盐碱地中有机质的行为和相互作用的基本问题，以及评估和开发使土壤更具生产力的实用方法(改良、轮作)。将在萨斯喀彻温省的棕壤和暗棕壤地区建立两个受盐分影响的土壤(盐碱地和盐碱地)的实地研究地点。强调了解改良剂对土壤和植物生产力的影响、盐类矿物的性质及其与有机质、碳和氮周转和固存的相互作用。申请人之前的工作考察了对非盐渍土壤进行的新型有机改良剂的影响，这使人们更好地了解了它们对土壤质量和植物生长的影响。继续这项工作以包括盐碱地是合理的，因为加拿大西部有600多万英亩受盐碱影响的土地。此外，近年来降雨量的增加和气温的升高导致了许多地区地下水位的上升和蒸发量的增加，从而加剧了盐度的扩散。气候变化可能导致盐碱化，但受盐分影响的土壤也通过改良和提高生产力为固碳提供了希望。然而，关于盐碱地有机质动态和养分循环的科学研究却很少。耕作前和耕作过程中存在的盐分导致植物生产力低下，导致这些土壤中的有机质含量低，以及从过去的化肥使用中积累的大量无机养分。使用有机材料进行改良，可以吸收阳离子和阴离子，改善水分关系，鼓励微生物活动，可能会促进耐盐牧草和轮作油菜和大麦等一年生作物更好的养分利用和生长。如果营养物质和盐分被有机物有效地隔离，预计也会对改善水质作出贡献。田间和受控环境研究将结合传统的化学、物理和基于同步加速器的新型技术，以更好地了解这些改良剂如何影响土壤盐分、水和空气关系、碳和氮的形态和周转、有机无机复合体的性质，以及它们促进耐盐牧草和一年生作物萌发和生长的能力。这项研究将有助于种植者适应和缓解气候变化以及经济繁荣。

The proposed research evaluates the impact of adding novel organic amendments, including biochar, humic material (leonardite) and composted manure, to chemically, physically and biologically challenged salt affected soils in Saskatchewan. Planned studies will address basic questions surrounding behaviour and interactions of organic matter in saline soils, as well as assessing and developing practical means (amendments, rotations) that will make the soils more productive. Two field research sites with salt affected soils (saline, solonetzic) in the Brown and Dark Brown soil zones of Saskatchewan will be established. Understanding the effect of the amendments on soil and plant productivity, nature of salt minerals and their interaction with organic matter, carbon and nitrogen turnover and sequestration is emphasized. Previous work by the applicant has examined impacts of novel organic amendments made to non-saline soils, which has led to a better understanding of their effects on soil quality and plant growth. A continuation of this work to include saline soils is justifiable as there are over 6 million acres of salt affected lands in Western Canada. Furthermore, increased precipitation and higher temperatures in recent years has led to higher water tables and increased evaporation in many regions that has contributed to the spread of salinity. Climatic variability can contribute to salinization, but the salt affected soils also offer promise for carbon sequestration through amendment and improvement in productivity. However, there has been very little scientific attention given to organic matter dynamics and nutrient cycling in saline soils. Low plant productivity caused by salinity present before and during cultivation contributes to low organic matter content in these soils as well as large amounts of inorganic nutrients that have accumulated from past fertilizer applications. Amendment with organic materials that can sorb cations and anions, improve water relations and encourage microbial activity will potentially promote better nutrient utilization and growth of salt tolerant forages and annual crops like hybrid canola and barley grown in rotation. A contribution to improved water quality is also anticipated if nutrients and salts are effectively sequestered by organic matter. Field and controlled environment studies will use a combination of traditional chemical, physical and novel synchrotron based techniques to better understand how the amendments influence soil salinity, water and air relations, carbon and nitrogen forms and turn over, nature of organo-mineral complexes, and their ability to promote germination and growth of salt tolerant forage grasses and annual crops. This research will contribute to grower adaptation and mitigation of climate change along with economic prosperity.