We demonstrate the potential importance of small-scale turbulence in the generation of radio emission from natural plasmas. This emission, being reliably detected and interpreted, probes small-scale turbulence in remote sources in the most direct way. The radiation emitted is called "diffusive synchrotron radiation" because it is related to shaking the electron distribution when passing through randomly distributed small-scale plasma inhomogeneities caused in turbulence. The emissivity is calculated and shown to be in the observable range. A further effect of inhomogeneities is transition radiation arising from fast particles which interact with small-scale density inhomogeneities. This emission process generates continuum emission below synchrotron and is applicable to some solar radio bursts. It serves for probing number densities. The effect of inhomogeneities on coherent emissions is either broadening or splitting of the spectral peaks generated by the electron cyclotron maser mechanism.