NASA Space Telescope Maps Magnetic Fields of ‘Lighthouse’ Pulsar - NASA Science (.gov)

Agronomy and crop science are the parts of agricultural science concerned with how field crops are grown, improved, and managed in soil and climate conditions that cannot be fully controlled. If you arrived here wanting the whole map of agricultural research, including animals, horticulture, food systems and rural economics, start with What Is Agricultural Science?; this page goes one level down and explains the crop-and-soil core of that map: what agronomists and crop scientists study, how they test ideas in the field, who organizes and funds the work, and where research administrators meet it. Agronomy is the science and practice of producing field crops — grains, oilseeds, forages, fiber and similar broadacre crops — while managing the soil, water, nutrients and pests that determine how those crops perform. It is an applied, systems-oriented discipline: an agronomist rarely studies one variable in isolation, because yield in a real field is the joint outcome of genetics, weather, soil, management timing and pest pressure.

IntroductionSurface acoustic wave (SAW) sensors have emerged as versatile platforms for a wide range of sensing applications1,2, including magnetic field detection and electrical current measurement3,4,5,6,7. These devices operate by generating surface acoustic waves on a piezoelectric substrate using interdigital transducers (IDTs)8. The propagating acoustic waves induce periodic strain in an overlying magnetostrictive film. An external magnetic field alters the elastic properties of this film, such as its Young’s and shear modulus, through the \(\:{\Delta\:}E\)-effect and \(\:{\Delta\:}G\)-effect, respectively9. The magnetoelastic SAW interaction with these field-dependent elastic constants modulates the SAW propagation velocity in a delay line setup3,6,7,10 or frequency in a resonator setup11,12. Recent studies have demonstrated limits of detection (LOD), such as 22 pT/Hz1/213, 55 pT/Hz1/214 or 126 pT/Hz1/215 all at 10 Hz for various SAW sensor setups, highlighting the strong potential of this technology for low-frequency magnetic field sensing.