Biochar derived from corn straw affected availability and distribution of soil nutrients and cotton yield

<div><p>Biochar application as a soil amendment has been proposed as a strategy to improve soil fertility and increase crop yields. However, the effects of successive biochar applications on cotton yields and nutrient distribution in soil are not well documented. A three-year field study was conducted to investigate the effects of successive biochar applications at different rates on cotton yield and on the soil nutrient distribution in the 0–100 cm soil profile. Biochar was applied at 0, 5, 10, and 20 t ha^-1 (expressed as Control, BC5, BC10, and BC20, respectively) for each cotton season, with identical doses of chemical fertilizers. Biochar enhanced the cotton lint yield by 8.0–15.8%, 9.3–13.9%, and 9.2–21.9% in 2013, 2014, and 2015, respectively, and high levels of biochar application achieved high cotton yields each year. Leaching of soil nitrate was reduced, while the pH values, soil organic carbon, total nitrogen (N), and available K content of the 0–20 cm soil layer were increased in 2014 and 2015. However, the changes in the soil available P content were less substantial. This study suggests that successive biochar amendments have the potential to enhance cotton productivity and soil fertility while reducing nitrate leaching.</p></div

Soil pH values after cotton harvested in 2013, 2014 and 2015.

<p>Soil pH values after cotton harvested in 2013, 2014 and 2015.</p

Influence of biochar application on crop yields and soil properties based on the literatures.

<p>Influence of biochar application on crop yields and soil properties based on the literatures.</p

Soil available P contents after cotton harvested in 2013, 2014 and 2015 (mg kg^-1).

<p>Soil available P contents after cotton harvested in 2013, 2014 and 2015 (mg kg^-1).</p

Soil NH₄⁺−Nin 0–100 cm soil after cotton harvested in 2013, 2014and 2015.

<p>Soil NH₄⁺−Nin 0–100 cm soil after cotton harvested in 2013, 2014and 2015.</p

Soil total Nin 0–100 cm soil after cotton harvested in 2013, 2014and 2015.

<p>Soil total Nin 0–100 cm soil after cotton harvested in 2013, 2014and 2015.</p

Cotton yield and yield components in response to biochar application at the rate of 0, 5, 10 or 20 t ha⁻¹ in 2013, 2014and 2015.

<p>Cotton yield and yield components in response to biochar application at the rate of 0, 5, 10 or 20 t ha⁻¹ in 2013, 2014and 2015.</p

Soil available K contents after cotton harvested in 2013, 2014 and 2015 (mg kg^-1).

<p>Soil available K contents after cotton harvested in 2013, 2014 and 2015 (mg kg^-1).</p

Fiber quality in response to biochar application at different rates.

<p>Fiber quality in response to biochar application at different rates.</p