Brian W. Bodah

Sediment and Nutrient Reduction in Irrigation Return Flows by Vegetated Filter Strips on Surface Irrigated Fields

Nonpoint sources account for nearly two-thirds of nutrient loading to the nations surface waters (Beutel et al., 2009; Sharpley et al., 2001). Vegetated filter strips can mitigate the effects of agricultural activities by presenting a physical barrier to sediment, nutrients, and pesticides being carried into streams (Munoz-Carpena and Parsons, 2004; Krutz et al., 2005). Filter strips may also reduce the flux of soluble nutrients through plant uptake or by supporting environmental conditions that favor chemical transformations such as denitrification (Haycock and Pinay, 1993; Cooper and Gilliam, 1987; Hickey and Doran, 2004).

A rapid morphological screening procedure for pea (Pisum sativum L.) under drought stress in greenhouse settings.

Aims: This work proposes a rapid morphological screening procedure for peas grown under drought stress aiming to provide phenotypic evaluations for further research. Materials and Methods: The plant yield and morphological changes of two widely grown pea cultivars (‘Aragorn’ and ‘Banner’) to drought stress was evaluated in this work. A total of eighty seeds of each pea variety were grown in a randomized completed block with four replicates in a greenhouse located in Moscow, ID. Plants were subjected to optimal irrigation (1400 ml as a control) and two treatments that reduced optimal irrigation rates by 40% (840 ml, moderate drought) and Short Research Article Bodah et al.; AJEA, 8(1): 68-74, 2015; Article no.AJEA.2015.148 69 60% (560 ml, severe drought) to induce drought stress. The test was repeated. Results: Varieties significantly (P<0.05) differed in their response to water deficiency. The variety ‘Banner’ appeared to be the most drought tolerant than ‘Aragorn’ with high values at control, moderate and severe as (85.00±4.08) cm, (87.21±3.26) cm and (66.02±2.92) cm respectively for total plant height, while the values for total dry weight were (3.65±0.20) g, (2.18±0.42) g and (1.26±0.10) g respectively. Similarly, there were significant (P<0.001) differences among treatments on growth parameters, with highest values recorded at optimal irrigation (1400 ml) as (21.52±2.42) cm, (62.18±4.68) cm, (0.24±0.04) g, (2.86±0.38) g and (2.30±0.18) seeds/pod for root length, shoot height, root weight, shoot weight and number of seeds respectively. The growth parameters decreased with a decrease of irrigation. Conclusion: As drought and stress conditions are expected to increase as global climate change progresses, breeding for drought is a promising area. Therefore, the variety ‘Banner’ has been identified as a potential parental material to be used in breeding for drought tolerance.

The Development and Evaluation of a Portable Rainfall Simulator Capable of Mimicking Variable Rainfall Patterns

Rainfall simulators present a useful tool for investigating the impacts of land management practices on runoff and erosion processes associated with storm events. However, it is critical that these simulators generate accurate rainfall patterns that are representative of the area studied. Researchers have developed rainfall simulators specific for use in a particular region, but these systems largely lack the capability to mimic rainfall characteristics across differing climactic regimes. This inflexibility can be problematic when working in a region that exhibits considerable rainfall variability. For instance, the Pacific Northwest displays a wide range of precipitation attributes that vary from maritime to mountainous to inland climates.

Impacts of Chemical Fallow Practices in Conservation Tillage Management Systems on Runoff and Erosion in the Pacific Northwest

Annual precipitation rates of 350-400 mm (14-16 in) in the western portions of the Palouse region in eastern Washington limit dryland wheat production. Growers typically adopt fallow management practices as part of a regular rotation to increase available soil moisture for the subsequent crop. Traditionally, repeated tillage (tillage fallow) has been used to mechanically kill weeds to eliminate transpirational water loss. Conservation tillage in the region often entails the use of direct seed tillage systems coupled with herbicide use as an alternative weed control agent during the fallow period (chemical fallow or chem-fallow) to minimize soil disturbance. Although previous studies have examined chemical fallow implementation, most research has been conducted at research field stations. The objective of this study is to evaluate the potential conservation benefits of using chemical fallow on operational farms, providing insight into runoff and erosion control under “real world” scenarios.