Enrol - UK Enroll - USA Enrol / Enroll "in" a course is far more common, at least in AmerEnglish.

The word ‘enrol’ is *really only used with reference to academic study or training courses. You enrol ‘at’ a college, etc. or ‘on’ a course of study or training. *there are a few other occasions when the word may be used for special purposes e g someone may be enrolled in the Hall of Fame, etc. - if a person is accorded a distinction (s)he is sometimes said to be enrolled in that institution ie added to the list [roll] of members.

As a verb ""enrol"",its object here is omitted by the context. You can imagine somewhat its object such as "agricultural land" ,which fact would drag you on the easy way to understand the part of the "at a college…" as a verbial element to modify the verb "enrol" to show the place where the action of the verb "enrol" happens. Only in this way would you understand the main structure of the original as: enrol (★on a course of "agricultural land"★) at a college. So there is nothing serious for you to consider the query about how to use the proper preposition after the verb "enrol". Chinese version (汉语译文): "enrol " 作为动词，此处它的宾语根据上下文省略了，你可以稍微想象一下它的宾语，例如想象它的宾语是"农业土地"(课程)，这样，就迫使你容易理解"…university…"是壮语成分来修饰动词"enrol" 表示这个动词的动作发生的地点。只有这种方法你也许才会理解原文的主要结构是: 在某大学注册(农业土地课程)。 于是，在动词enrol后面如何使用正确的介词这种疑问了就是小问题了(不是问题了)。

为了让你更加明白"宾语省略"请看截图: