Nitrogen Fertilizers and Nitrogen Management in Agriculture

**27**

**Chapter 3**

**Abstract**

Nitrogen Management in

Conservation Agriculture

must be tailored to crop and soil types and location-specific.

soil N test value, sensor-N guidance

**1. Introduction**

fied crop rotation:

**Keywords:** N immobilization, adaptive N fertilization, crop N demands,

of the cropped area, in addition to no interrupting tillage.

100%, however, surface soil cover of 30% is seen as adequate.

Conservation agriculture (CA) is a resource-efficient system that is capable of increased soil quality, crop productivity, and environmental sustainability [1]. CA system provides multiple ecosystem services and promotes agrobiodiversity ([2], Montpellier [3]). It is characterized and quantified by three principles practised simultaneously, namely; zero/minimum tillage; permanent soil cover; and diversi-

• Continuous zero or minimum soil tillage: direct seeding or planting into undisturbed or untilled soil, to maintain or improve soil organic matter content, soil structure, and soil health. The disturbance area must be less than 15 cm or 25%

• Permanent organic matter soil cover with cover crops or crop residues: this shields the soil surface, conserves nutrients and water, promotes soil biological activity, and contributes to weed management. Soil cover should be preferably

Transitioning to conservation 'sustainable' agriculture (CA) from the conventional 'industrial' agriculture often increase nitrogen (N) limitation, particularly in the first few years. Inadequate N availability is associated with the permanent crop residues on the soil surface. The soil available N for crop uptake is immobilized by microbial sources of organic residues mineralization. The increase in N immobilization contributes to yield declines, and thus, researchers are advocating for the inclusion of N management as the fourth principle in CA. The challenge for CA under optimized N fertilization is how to reduce environmentally-damaging greenhouse gases (GHG) emissions from yield-related productivity. This paper focuses on efficient N management under CA system. Here, we showed the impacts of adaptive N management on crop yields increase, soil health enhancement, and greenhouse gases mitigation. We conclude that efficient N management using innovative technologies and good agronomic practice can scale-up the adoption of CA. An adaptive N management in CA can maintain environmental benefits while contributing to improved soil health and crop productivity. Moreover, the implementation of adaptive N management

*Anthony Imoudu Oyeogbe*

#### **Chapter 3**
