**Passage 1: Crop Yield**
The productivity of agricultural production, often referred to as "yield," has been a key focus in agriculture. In the past, increases in agricultural productivity were primarily achieved by expanding the area of farmland. However, as the expansion of arable land reached its limits, humans began to focus on improving yield through other methods to increase production. Two main approaches mentioned are **irrigation** and the use of **fertilizers**. Historical data indicates that fertilizers were highly effective during a certain period, but later their marginal utility decreased, causing the growth rate of crop yields to slow down (though it still increased). Between 1990 and 2000, the growth rate slowed to almost 1%.
The passage also mentions the development of high-tech crops in countries like Japan, Europe, and the United States, which have contributed to increases in food production. Earlier in the article, **photosynthesis** is discussed as a fundamental process in plant growth. The author then argues that there is still potential for increasing food production. As an example, the article highlights a local technology used in Africa, where crops are planted alongside trees. This method promotes higher crop yields by leveraging the symbiotic relationship between crops and trees.