How does overtillage harm soil? a. overtillage can increase the rate of humus decomposition. b. overtillage can increase the water carrying capacity of soil. c. overtillage can result in increased soil compaction. d. overtillage can increase the organic material in soil. it's either a or d but i'm not sure

Over-tillage can be defined as an excessive tillage that means the preparation of soil by mechanical means- like digging, stirring etc.

When this is done in abundance, then humus decomposition rate is increased. Humus is the dark organic matter formed in the soil when plant and animal matter decays. When a lot of matter is tilled up, air does not pass through it and it results in early decomposition that affects the soil properties.

So, correct answer is - Overtillage can increase the rate of humus decomposition.

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