When farmers plant crops, they pay great attention to the row orientation of the crops because different orientations affect the amount of sunlight the crops receive and how the plants utilize it, which in turn significantly impacts the yield.
This fact has been proven through practice. Scientists conducted an experiment: in northern regions, barley planted in north-south rows yielded several tens of kilograms more per acre compared to barley planted in east-west rows. The same result was observed with potatoes, where north-south rows yielded over a hundred kilograms more per acre than east-west rows. Additionally, the starch content in the tubers of north-south row potatoes was higher.
Chinese farmers have the same experience. Whether planting wheat, rice, or vegetables, they generally plant in north-south rows.
Why is this?
Let’s observe the impact of sunlight on the crop rows!
We know that when crops are still very young, if they are planted in north-south rows, sunlight can shine on the entire row of seedlings from morning till evening, allowing the young plants to receive sufficient sunlight. This is very beneficial for the leaves’ photosynthesis.
At noon, when the sun is high in the sky, it is slightly to the south. Thus, the crops partially shade each other at this time. However, this is also beneficial to the crops because it prevents excessive heat from the midday sun.
Therefore, planting crops in north-south rows provides relatively suitable light and heat conditions. With sufficient light and heat, plants’ photosynthesis is more vigorous, enabling them to produce more starch and other organic substances, thereby increasing crop yields.
Conversely, crops planted in east-west rows have the opposite effect. In the morning and evening, sunlight shines along the planting rows, causing the crops to shade each other and affecting the leaves’ photosynthesis.
At noon, the sun shines directly on the crops, and the high temperature is still unfavorable for the leaves’ photosynthesis. Sometimes, it even causes the leaves to completely stop working for several days. Thus, less starch is produced, resulting in lower yields.
However, in the relatively hot southern regions, it is different. There, crops often yield more when planted in east-west rows because this helps lower the temperature and prevents the crops from becoming too hot, which is also harmful to them.