Abstract: A novel NMR principal detector element of the present invention comprises a NMR-active inductor in a radio frequency (RF) resonance circuit, and mitigates the distortions in a static magnetic field caused by the introduction of a toroid cavity NMR detector. The RF resonance circuit includes a novel principal detector element, capacitor elements, and a sample chamber (the cavity). The novel principal detector element defines the NMR active portion of the inductance of the electronic resonance circuit. In one embodiment of the invention, the novel principal detector element includes two hemispheres connected by a central rod. The central rod can be of any length and diameter, and the hemispheres can be of any diameter. A typical embodiment of the invention would include a rod that is 2 cm long having a diameter of 1 mm, and hemispheres having a diameter of 5 mm.

Abstract: Apparatus comprising a frame carried by an elongated and laterally extending bar and having mounted thereon a first pair of rotatable trash wheels and a second pair of rotatable trash wheels longitudinally spaced behind the first pair of rotatable trash wheels and forward of a furrow opener. The first pair of rotatable trash wheels is angularly disposed toward each other forming a first angle therebetween and staggered such that one rotatable trash wheel contacts soil forward of the other rotatable trash wheel. The second pair of rotatable trash wheels is angularly disposed toward each other forming a second angle therebetween greater than the first angle. The apparatus cuts and clears trash from minimally and untilled soil.