Soru

Passage A

For decades, industrial agriculture has relied heavily on synthetic fertilizers and intensive tilling to maximize crop yields. While these methods initially produced high outputs, they have led to severe soil degradation, particularly through wind and water erosion. This degradation has diminished the soil's natural capacity to sustain crops without ever-increasing chemical inputs. To combat this loss of arable land and restore agricultural sustainability, conservationists increasingly advocate for the implementation of cover crops—non-harvested plants such as clover, rye, or vetch sown during off-seasons.

The primary benefit of cover crops lies in their ability to physically protect the soil surface. When fields lie fallow between main growing seasons, they are highly vulnerable to the elements. Raindrops falling on bare soil dislodge soil particles, while wind sweeps away the nutrient-rich topsoil. Cover crops establish a living canopy that cushions the impact of rainfall and anchors the soil with extensive root networks. Furthermore, these roots create channels that improve soil structure, increasing water infiltration and reducing harmful runoff. This physical barrier ensures that valuable soil particles remain in place rather than washing into nearby waterways.

Beyond physical stabilization, cover crops play a critical role in nutrient management. Leguminous cover crops, for instance, form symbiotic relationships with nitrogen-fixing bacteria, drawing nitrogen from the atmosphere and storing it in the soil. When these cover crops are eventually terminated and incorporated back into the ground, they release this accumulated nitrogen, along with other organic matter, back into the soil. This natural fertilization reduces the farmer’s dependency on expensive and environmentally damaging chemical additives, ensuring that the soil remains fertile and productive for future planting cycles. Ultimately, cover crops serve as an indispensable tool for preserving the physical integrity and nutrient levels of agricultural soils, paving the way for more sustainable farming practices.

Passage B

Modern agricultural science has shifted its focus from merely maintaining the physical structure of soil to understanding the complex biological communities that thrive beneath the surface. Soil is not merely an inert medium for holding plants upright; it is a dynamic, living ecosystem populated by billions of bacteria, fungi, and micro-arthropods. The health of this underground web is directly linked to the health of the crops grown above it, and traditional fallow periods threaten this delicate balance by depriving soil organisms of sustenance.

When a field is left bare after harvest, the subterranean food web is starved of its primary energy source: plant roots. Living roots exude carbon compounds, sugars, and amino acids that feed soil microbes. Without these root exudates, microbial populations plummet, leading to a sterile soil environment that is highly susceptible to pathogens. Planting cover crops solves this biological crisis. By maintaining continuous plant growth throughout the year, cover crops provide a constant supply of organic carbon to the rhizosphere, supporting a diverse and active microbial population that keeps the soil system alive.

This biological activity has profound implications for crop health. Mycorrhizal fungi, which associate with cover crop roots, form networks that help subsequent cash crops access water and essential minerals like phosphorus that would otherwise remain unavailable. Additionally, a diverse soil microbiome suppresses disease-causing organisms through competition and natural predation. While the physical benefits of soil cover—such as erosion control—are certainly valuable, the true power of cover crops lies in their ability to sustain the underground biological engine. By nurturing a diverse microbial community, cover crops ensure long-term agricultural sustainability and resilience against environmental stressors.

Based on both passages, the authors of Passage A and Passage B would most likely agree with which of the following statements regarding cover crops?