Effect of Straw Removal and Irrigation Systems on Nutrient Availability and Soil Chemical Quality

Resumo

Soil chemical quality is a critical factor for agricultural productivity, and
management practices such as straw removal can directly impact nutrient availability.
Nutrients such as potassium, calcium, magnesium, and micronutrients play essential
roles in plant growth and development, as well as in promoting microbial activity. Straw
removal and different irrigation systems can alter the dynamics of these nutrients,
influencing both plant health and soil biodiversity. Objective: This study aimed to
investigate the effect of straw removal and irrigation systems on nutrient availability and
soil chemical quality in sugarcane cultivation areas.
Methodology: The experiment was conducted in sugarcane fields in the Goianésia region,
Goiás, Brazil. Soil samples were collected from areas under sprinkler, pivot, and rainfed
irrigation systems, with and without straw removal for one and two years. Soil chemical
analyses were performed to quantify macronutrients (potassium, calcium, magnesium)
and micronutrients (boron, iron, manganese, zinc). Data were subjected to statistical
analyses to identify differences between treatments. Main Results: Results showed that
two years of straw removal significantly impacted potassium and calcium levels,
especially in pivot-irrigated areas. Continuous straw removal reduced potassium
availability, which may negatively affect beneficial soil microorganisms such as
mycorrhizal fungi. Additionally, areas without straw removal showed higher levels of
micronutrients, such as iron and manganese, suggesting that straw presence contributes
to the retention of these nutrients. Conclusion: Prolonged straw removal affects the
availability of essential soil nutrients, particularly potassium and calcium, which can
impact agricultural productivity and soil microbial health. Areas without straw removal
showed better micronutrient retention, highlighting the importance of straw in maintaining
soil chemical quality. Therefore, management practices that preserve straw cover can
contribute to more sustainable agriculture.