**5. Potential of reducing carbon and water footprints for sustainable maize production**

#### **5.1 Maize production and carbon footprint**

Maize cultivation has traditionally relied on conventional tillage methods involving plowing. However, due to factors such as cost, natural conditions, and environmental concerns, there is an increasing adoption of noninversion systems in modern maize production. These noninversion systems typically involve reduced tillage, where no-till seeders are used for substituting plowing and contributing to sequester more soil carbon. By promoting adoption of the no-tillage system, the seeders put seeds directly into uncultivated soil for low disturbance and high reduction of GHG [57].

In order to protect the soil and the environment, the use of noninversion tillage techniques and the retention of a minimum of 30% of plant residues on the field, known as conservation tillage, are of particular importance. These practices help preserve soil structure and reduce erosion while promoting the conservation of organic matter.

Enhancing the management of soil cultivation practices to promote the sequestration of organic carbon in the soil is crucial for mitigating greenhouse gas (GHG) emissions in agriculture. Recent research conducted by Holka et Bienkowski [57] in Wielkopolska in Poland, has highlighted that the adoption of no-tillage methods combined with substantial crop residue retention can effectively reduce GHG emissions in maize production. Irrespective of the specific tillage system utilized, the process of mineral fertilization emerged as the key contributor to GHG emissions. Developing

*Sustainable Maize Production and Carbon Footprint in Arid Land Context: Challenges… DOI: http://dx.doi.org/10.5772/intechopen.112965*

low-emission technologies necessitates careful consideration of the associated risks, particularly related to nitrogen fertilizer usage. To minimize emissions from agricultural fields and simultaneously reduce raw material consumption in fertilizer production, optimizing fertilization practices becomes essential, taking into account natural constraints and soil conditions, as well as the desired crop productivity levels.

By considering the sequestration of organic carbon (C) in the calculation of greenhouse gas (GHG) emissions, the net carbon footprint (CF net) of grain maize production was found to be significantly reduced. Compared to the baseline CF value, the CF net values were lowered by 42.9% in the conventional tillage (CT) system, 72.1% in the reduced tillage (RT) system, and 78.3% in the no-tillage (NT) system. When GHG emissions were analyzed per ton of maize produced, the inclusion of C sequestration showed the most substantial impact in reducing total GHG emissions in the NT and RT systems, with reductions of 78.3% and 72.1%, respectively. Effective management of maize crop residues, such as leaving larger amounts of residues in the field, played a significant role in preventing C losses promoting its sequestration, and reducing the carbon footprint in maize production.

#### **5.2 Maize production and water footprint**

Water footprint (WF) is an indicator that plays a vital role in promoting sustainable maize production by addressing both water consumption and pollution. Maize is a major global crop, and understanding its water footprint is crucial for ensuring responsible water management practices. It provides a new approach for assessing water resource utilization in agriculture.

The WF of crop production serves as a comprehensive indicator that encompasses the various types of water consumption, quantities utilized, and environmental impacts throughout the entire crop growth period [58]. It provides a holistic understanding of water consumption and its associated implications during the process of crop cultivation. The WF takes into account not only the direct water usage by the crops but also the indirect water footprint related to the production and use of inputs such as fertilizers and pesticides.

The WF considers both the blue water footprint (water from surface or groundwater sources) and the green water footprint (rainwater stored in the soil). Additionally, it accounts for the gray water footprint, which refers to the volume of water that is required to assimilate polluted water [59]. In a study conducted by Sun et al. [58] in Beijing, they found that WF had decreasing trends because of the reduced green WF due to the change in climate and the rising temperature and water scarcity, while the gray WF increased because of chemical fertilizers and pesticides. They concluded that the gray WF should be controlled to achieve a sustainable maize production. In another study conducted in Italy by Borsato et al. [60], they affirm that soil conservation tillage systems can reduce the gray WF by 10%. The study focuses on soil tillage systems and variable rate application as means to reduce the gray WF. It emphasizes that the interaction between soil tillage systems and soil management plays a significant role in reducing the gray WF. They found that minimum Tillage with Precision Farming shows lower gray WF values, both in terms of water usage per ton and per hectare. Soil tillage systems combined with variable rate application exhibit a higher reduction in gray WF. To reduce water pollution, prioritizing the reduction of insecticides and herbicides, using chemicals with a lower gray WF, and implementing sustainable soil management practices are recommended.
