**1. Introduction**

The conversion of grasslands and forest to croplands is not sustainable if conversion occurs on land not suitable for crop production and if the soil loss rates exceed the rates of soil formation. In semiarid regions, soil erosion is one of the critical factors leading to soil degradation [1]. Erosion is increased when the vegetation cover is destroyed by cultivation [1, 2]. The resulting erosion can reduce the productivity by soil structural degradation as well as by reducing water holding capacity, water and nutrient runoff, and changing other soil properties [3, 4].

The Northern Great Plains (NGP) has undergone extensive management changes since homesteading in the 1880s. These management changes are the result of markets, technologies, and climate variation over time. Climate and market variability results in boom and bust cycles [2]. For example, during World War I, farmers optimized their profits by plowing and planting grasslands with annual crops. The period of high yields was followed by drought during the 1930s which resulted in the dust bowl and bust. A recent boom occurred between 2006 and 2012 due to increase in maize and soybean price. During this timeperiod, Reitsma et al. [4] reported that 730,000 ha of grassland was converted to cropland.

During rapid land conversion periods, grasslands are often converted to cropland. This conversion can strengthen the financial resources of individual farms while simultaneously reducing wildlife habitat [5]. Thus, land conversion from grasslands to croplands creates the classical dilemma of balancing economic development with environmental impacts. Between 2008 and 2011, all across the USA, 23.7 million acres of grassland, shrub, and wetland were converted to agricultural land, and 3.2 million acres of wildlife habitat disappeared in North and South Dakotas alone [6]. Grasslands are one of the most threatened and least protected ecosystems.

Worldwide, the NGP ecoregion in North America is considered one of best remaining opportunities for grassland maintenance [7]. Similarly, other adverse side effects of land-use change are increased greenhouse gas emissions [8, 9], reduced water quality [10], and higher soil erosion [11, 12]. In the NGP, the adoption of management practices that improve soil health and minimize soil degradation is critical to insure long-term sustainability [13–19]. We believe that increasing the adoption of sustainable management practices requires a clear understanding of factors driving the land-use change. Reitsma et al. [4] reported that land-use change most likely resulted from many factors including recent technological improvements, land ownership structure changes, climatevariability, various governmental policies, crop prices, and aging workforce [4, 14, 20, 21].

Technology improvements, such as the development of new planting equipment and the wide-scale adoption of transgenic crops, have provided the opportunity to seed annual crops in areas that previously were considered unsuitable for crop production [14]. Moreover, complex interaction of various factors like climatic variability, soil quality, topography, and socioeconomic factors may influence individual decisions [22, 23]. In the NGP, higher rainfall and temperatures linked to climate change were important [7, 24].

From soil erosion perspective, the conversion of grasslands to cropland may be sustainable if conversion occurs on suitable land type [4]. One approach to assess suitability is the land capability classification (LCC) approach. In this approach, soils with LCC values ≤ 4 are generally considered sustainable for annual crops if appropriate management practices are followed. Soils with LCC values ≥ 6 are not considered suitable for annual crops. Soils with a LCC value of 5 may be prone to flooding. The number of restrictions increases as the LCC value increases from 1 to 4 and from 6 to 8. However, Rashford et al. [25] found that between 1978 and 2008, 0.4 million hectare of cropland increased and most conversions occurred on land are considered suitable for crop production (LCC ≤s 1–4). Rashford et al. [25] also reported that grassland with LCC ≤ 2 has a 30–50% greater probability of being converted to cropland than grassland with LCC values of 3 and 4.

In light of current pressure on land and various forces driving land-use change, it is essential to examine the dynamics of land changes. The objectives of this study were to calculate the rate of land-use change from 2006 to 2012 and from 2012 to 2014 in South Dakota and Nebraska and assess if land-use changes were sustainable. This region was selected as a model system because it is located in a climate transition zone and it has a humid continental climate on the eastern border and semiarid climate on the western border [26, 27].

**5**

**Figure 1.**

*Soil and Land-Use Change Sustainability in the Northern Great Plains of the USA*

South Dakota and Nebraska were selected as model systems because these states contain a wide range of soil, crops, and climate which are representative of other larger areas; both states have a large production capacity for livestock and annual crops; most of the soils were developed in tall and mixed grass prairies; they are located in climate transition zone; and the two states have different access to irrigation water. This region receives most of its precipitation in the spring and fall [14]. The most common annual crops in South Dakota include maize (*Zea mays* L.), soybean [(*Glycine max* (L.) Merr.], and wheat (*Triticum aestivum* L.). In South Dakota, rainfall decreases from east to west, and temperatures decrease from South to North. Additional information on characteristics of South Dakota soils is available in Reitsma et al. [4] and Clay et al. [13]. Farmers in this region use crop rotations that include maize, soybean, wheat, sunflower, canola (*Brassica napus* L.), barley (*Hordeum vulgare* L.), lentil (*Lens culinaris* Medik.), flax (*Linum usitatis-*

Eastern Nebraska has a humid continental climate, whereas the western region has a semiarid climate [26, 27]. Eastern part of Nebraska has fertile, moist, and warm soil making it well suited for maize and soybean production. It consists of

*South Dakota and Nebraska states in the US map along with USDA's National Agricultural Statistics Service* 

*(NASS) reporting regions. (Source of Data, USDA-NASS).*

*DOI: http://dx.doi.org/10.5772/intechopen.84781*

*simum* L.), and pea (*Pisum sativum* L.).

**2. Materials and methods**

*Soil and Land-Use Change Sustainability in the Northern Great Plains of the USA DOI: http://dx.doi.org/10.5772/intechopen.84781*
