In economics, land refers to all natural resources - the soil, minerals, water bodies, forests, climate, and everything provided by nature. On its own, land is passive; it cannot produce goods or services without intervention. Land as a factor of production is made useful through the application of human effort, which in economics is called labour.
Labour is the human physical and mental effort applied to natural resources to transform them into useful goods and services. Without human effort, fertile land would remain uncultivated, mineral deposits would stay underground, and rivers would not be harnessed for irrigation or power. It is the combination of land and labour that initiates the production process.
While fertilizer and machines can enhance the productivity of land, they are specific tools or inputs rather than the fundamental factor that makes land useful. Fertilizer is a material input, and machines represent capital (another factor of production), not the basic force that activates land. Acts of nature create land itself but do not make it productive in the economic sense - that requires deliberate human activity.