Jonny was a very religious man who belonged to the Lutheran congregation in Balaklava. It is said that he was one of the first to develop the stump-jump plough (a labour saving device to remove mallee tree stumps), for which he was awarded a medal for exhibiting it at the Port Wakefield Agricultural and Horticultural Society in 1885. Others, like Smith from Maitland, South Australia patented the invention. The stump-jump plough is now regarded as one of the most significant inventions that changed the face of the Australian countryside as it permitted land to be cleared at an unparalleled rate.