Soil Fertility Evaluation and Control presents the theoretical background for practical applications of scientific work on soil fertility. The book emphasizes the use of response curves as the basic biological standard for both evaluation and control, and it discusses soil testi…
Nutrient supplies and crop yields: response curves. Liebig's "law of the minimum". Mitscherlich's "law of physiological relationships or "effect law of the growth factor". Factors affecting the shape of response curves. Limitations of response functions. Other response functions…
This study explores 20 years of Minnesota regional phosphorus (P) management data across agricultural landscapes and how these are modeled by the Minnesota Phosphorus Index (MNPI). Nutrient-loading and farm management records from 1999-2019 were compiled across 17 different Minn…
Seaweeds have been receiving increased interest from the fisheries and aquaculture industries in recent years, with red algae continuing to be one of the more important components of seaweed aquaculture representing 54% of the harvested biomass (around US 6.3 billion). These sea…
Climate change poses a growing threat to freshwater ecosystems and water quality. This dissertation examines the relationship between changes in climate and two key water quality parameters: the transport of nitrogen within rivers, referred to as nitrogen loading, and river temp…
Changes in climate, land-use, and land cover alter estuarine nutrient loads, particularly in systems with strong land-sea connectivity. Process-based water quality models are commonly used to assess how upstream changes in hydrology and land management influence downstream estua…
Constraints to increased agricultural production in Niger include low and variable rainfall, low water retention and poor soil fertility. Population pressure has shortened the fallow period in most regions. The main research problem in this thesis is to identify the determinants…
High fertilizer prices coupled with environmental effects of fertilizers have created serious concerns among scientists and the general public. Studies were conducted to evaluate the (a) environmental and economic benefits of replacing nitrogen (N)-fertilized grass with grass-le…
With the increase in population and food demand, and, the limit of water and land available, novel methods are needed to produce food. Over the last decades, there has been a growth in controlled environments, especially greenhouses, and the use of hydroponic systems to produce …
This thesis examines the use of specific agricultural inputs in crop yields of sugarcane, maize, wheat, and rice in the three major provinces of Pakistan from 1985 to 1989. The effect of inputs like fertilizers on crop yields is expected to be positive, however the evidence sugg…
"Soil and Fertilizers: Managing the Environmental Footprint presents strategies to improve soil health by reducing the rate of fertilizer input while maintaining high agronomic yields. It is estimated that fertilizer use supported nearly half of global births in 2008. In a conte…
