Abu Ubayd says, regarding the hadith of Sayyiduna Uthman (may Allah be pleased with him), that he said: It has reached me that some of you go out to your rural lands, either for trade or for collecting taxes, or you take your animals out to pasture, and then shorten the prayers. Do not do so; shortening the prayer is only for one who sets out on a journey or who is facing an enemy.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 5402