Effects of Organic Amendments on the Improvement of Soil Nutrients and Crop Yield in Sandy Soils during a 4-Year Field Experiment in Huang-Huai-Hai Plain, Northern China

To address the low productivity of sandy farmlands, our study aimed to conduct a comparative on effects different organic amendment (OA) inputs for potential improvement crop yield and soil quality in alkaline farmlands through selection suitable OA. This set up straw (ST) returning as control chemical fertilizer (CF) treatment side control, chose three OAs treatments, including pig manure (PM), biogas residue (BR), biochar (BC), improving fertility, with all amendments having matched doses nitrogen (N). The experiment was conducted at Wuqiao Experimental Station (37°41 N, 116°37 E) China Agricultural University Hebei Province, China, from October 2012 September 2016. cropping rotation winter wheat (Triticum aestivum L.)-summer maize (Zea mays L.) system. Through consecutive four-year field experiment, principal results showed that types OA application significantly increased carbon 1.46 g kg−1 8.24 kg−1, total N 0.21 0.64 available potassium 55.85 mg 288.76 phosphate 4.86 65.00 0–20 cm layer. BR most effective nutrients compared ST. PM treatments were more conducive promoting by 6–20% than ST, BC reduced 19% summer 8%. As improved nutrient content yield, these top choices transforming low-yield farmlands.