The invention discloses a farmland mulching film residue monitoring method, which comprises sampling point arrangement, soil layer sample sampling, farmland mulching film residue sample screening and mulching film sample
impurity removal, the sampling point arrangement adopts nylon grids and fixing piles, the grid of the nylon grids is 1 meter square, sampling grids are marked in the nylon grids according to a plum blossom
point method, a snake-shaped method or a
diagonal line method, and the sampling grids are arranged in the fixing piles. Every two adjacent sampling grids in the nylon grids are spaced at more than two grids in the long side direction, two fixing piles are nailed on each of a first short side
ridge and a second short side
ridge of the sampling plot, the four fixing piles are connected through
engineering lines to form a datum line, the nylon grids are unfolded in the datum line, and the sampling plot is formed. The short edges on the two sides of the nylon grid are respectively overlapped and fixed with the datum lines of the long edges on the two sides, and the sampling grid is found. And a
nylon mesh method is adopted to determine the
quadrat position, so that repeated sampling
quadrat among years is avoided, and the method is convenient and time-saving.