cultivated horizon

基本解释

The cultivated horizon was too shallow and machinery cultivation can increase thickness of cultivated horizon effectively.
耕层土壤厚度过浅，机耕可有效增加耕层厚度；
Soil samples of cultivated horizon from Gongpeng town were analyzed in 1998 and the results were compared with that in 1990.
1998年对黑土区（弓棚镇）的耕层土壤养分进行分析，并与1990年该区土壤的化验结果进行了比较。
Therefore, "wave type" section cultivated horizon may occur drier phenomenon much easier than "flat type" section. This may be the main reason why drier phenomena easily happen in the black soil.
“波浪型”剖面耕层土壤比“平面型”剖面更容易发生干旱现象，这可能是黑土区土壤易出现干旱现象的主要原因。