Crops & Soils最新文献

Cover: The application and fate of nutrients are two of the biggest questions agriculture faces today, affecting everything from profit margins to water quality. Researchers work to examine the issue from all angles, such as the kinds of fertilizers widely used in the United States to how the topography of a field can impact the distribution and runoff of nutrients. In this issue, we look at two recent research articles that approach these questions from different angles. One sees the nitrogen content of ammonium phosphate fertilizers as a “blind spot” in nitrogen budgets. The other sees farmed prairie potholes as potential “hot spots” for nutrient runoff downstream. See story on page 4. Photo courtesy of Adobe Stock/Yaroslav.

This article is reproduced from Chapter 6 of the new book, Salinity and Sodicity: A Growing Global Challenge to Food Security, Environmental Quality and Soil Resilience, in a slightly modified form. The book is available for purchase from Wiley.com or Amazon.com. The article covers the use of electromagnetic (EM) sensors for measuring apparent electrical conductivity (EC_a). In the field, electrical conductivity (EC) can be measured by two primary approaches: physical contact and electromagnetic (EM) induction. With physical contact, a current is injected into the soil, and the detector measures the resulting voltage. An EM meter does not make direct contact but uses a coil to produce an EM field. A sensor then measures the soil-induced changes to the original EM field. Both types of sensors measure the EC_a, which is different from laboratory-derived EC values. When using EC_a sensors, it is important to remember that they are sensitive to many factors, including salinity, soil moisture, bulk density, soil texture, and temperature. The purpose of this article is to provide an overview on the use of EM sensors to provide examples on the use of these sensors in the field. Earn 1.5 CEUs in Soil & Water Management by reading this article and taking the quiz at https://web.sciencesocieties.org/Learning-Center/Courses.

The application and fate of nutrients are two of the biggest questions agriculture faces today, affecting everything from profit margins to water quality. Researchers work to examine the issue from all angles, such as the kinds of fertilizers widely used in the United States to how the topography of a field can impact the distribution and runoff of nutrients. In this article, we look at two recent research articles that approach these questions from different angles. One sees the nitrogen content of ammonium phosphate fertilizers as a “blind spot” in nitrogen budgets. The other sees farmed prairie potholes as potential “hot spots” for nutrient runoff downstream. Earn 1 CEU in Nutrient Management by reading this article and taking the quiz at https://web.sciencesocieties.org/Learning-Center/Courses.

In dryland region of the inland Pacific Northwest (iPNW), the two-year winter wheat–fallow rotation is associated with wind erosion and a decline in soil organic carbon (SOC) and overall soil health. The use of biosolids, produced as by-products of municipal wastewater treatment, in agriculture is gaining traction as an effective way to improve SOC and nutrient availability. While immediate benefits of biosolids application have been studied to some extent, there is still a lack of research-based information on the persistence and residual effects of biosolids applications in the low-precipitation region of the iPNW. Therefore, a study was conducted to address that gap by assessing the legacy effects of biosolids, seven years after their application. Earn 0.5 CEUs in Soil & Water Management by reading this article and taking the quiz at https://web.sciencesocieties.org/Learning-Center/Courses.

Black-eyed pea is a pulse crop and a subspecies of cowpea. Historically, most of the black-eyed pea grown for grain has been in California. As water availability declined in the region, production shifted to Texas in the 1990s and to Arizona in the early 2000s. The pulse-crop-producing regions of Nebraska, Kansas, and Colorado have seen an increase in black-eyed pea acreage over the past nine years as an effort to maintain U.S. production levels. Black-eyed pea is a suitable cash crop legume to enhance the dryland cropping rotations. What once was a crop grown on irrigated acres in the arid West has been found to flourish on the dryland and limited-irrigation acres of the High Plains. Earn 0.5 CEUs in Crop Management by reading this article and taking the quiz at https://web.sciencesocieties.org/Learning-Center/Courses.

There is a substantial pool of mineral nutrients contained in wheat residue, concentrated in K, which has substantial economic value. Given this value, it is important for wheat producers to weigh the relative benefits of residue harvest, which gives immediate but marginal revenue gains, and residue retention, which has multifaceted benefits that include substantial savings on future nutrient costs. Persistent removal of nutrients from agronomic systems through residue harvest affects soil nutrient availability in the short- and long-term, and the timing and magnitude of these changes will depend on the cropping system and soil. Earn 1 CEU in Nutrient Management by reading the article and taking the quiz at https://web.sciencesocieties.org/Learning-Center/Courses.