Document Type

Thesis - Open Access

Award Date

2017

Degree Name

Master of Science (MS)

Department / School

Agronomy, Horticulture, and Plant Science

First Advisor

Sandeep Kumar

Abstract

Integrated crop-livestock system (ICLS) is helpful in diversifying a farm for improving its long-term sustainability and economic benefits. In the United States, the ICLS has been increasing in recent years because of its economic and environmental benefits. However, the impacts of ICLS on soil quality is not well documented in North Dakota. The objective of our study is to assess the impacts of cropping sequences and cattle grazing on the selected soil properties in the crop diversity and livestock integration practice. This study site was established in 2010 at the Dickinson Research Extension Center, Dickinson, North Dakota. The study design was a randomized complete block design with 3 replications. Treatments were included the five 5-yr cropping sequences and one continuous 5-yr spring wheat (control, CNT). The five crop rotation crops were sunflower (Helianthus annuus L.)-spring wheat (Triticum aestivum L.)-multi-species cover crop-corn (Zea mays L.)-field pea (Pisum sativum L.) and barley (Hordeum vulgare L.) (S1), spring wheat-cover crop-corn-pea/barley-sunflower (S2), cover crop-cornpea/ barley-sunflower-spring wheat (S3), corn-pea/barley-sunflower-spring wheat-cover crop (S4), and pea/barley-sunflower-spring wheat-cover crop-corn (S5). The cover crop included winter triticale (Triticosecale Wittm.) and hairy vetch planted in September for spring hay production the following June. A mixture of seven species cover crops was planted for fall and winter cow grazing. Grazing treatment included grazed and ungrazed. Soil samples were collected from 0-5, 5-15, 15-30, 30-45, and 45-60 cm in June 2016 and April 2017. Soil bulk density (BD), soil organic carbon (SOC), total nitrogen (TN), soil wet aggregate stability (WAS), soil water retention (SWR), carbon and nitrogen fractions (labile, stable, and inert), microbial biomass carbon, urease and betaglucoside enzyme activity were measured in this study. The results showed that the cropping sequences under ICLS numerically increased SOC, urease, beta-glucoside enzyme activity and decreased the BD values at 0-5 cm depth, however, differences were not significant. Grazing only impacted the soil BD at shallow depth (0-5 cm). It can be concluded that soil compaction created by livestock can be alleviated by crop rotation, and ICLS is a good practice to be conducted in North Dakota which brings beneficial environmental impacts and economic return. Future study is needed to characterize the long-term grazing and cropping sequences impact on soil quality.

Library of Congress Subject Headings

Soils -- Quality -- North Dakota.
Integrated agricultural systems.
Cropping systems.
Grazing.
Crops and soils.

Description

Includes bibliographical references (pages 68-74)

Format

application/pdf

Number of Pages

136

Publisher

South Dakota State University

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Rights Statement

In Copyright