Polymeric salt-tolerant and water-retaining fertilizer and preparation method thereof

A preparation method of polymeric salt-tolerant and water-retaining fertilizer comprising following raw materials in parts by weight:

• 4465-5880 parts of fertilizers, 2292-3563 parts of water-retaining agents and 850-2850 parts of clays;
• wherein the fertilizer comprises following raw materials in parts by weight:
• 1000-1200 parts of urea, 800-1000 parts of diammonium phosphate, 500-700 parts of potassium sulfate, 1000-1200 parts of ammonium sulfate, 350-500 parts of potassium dihydrogen phosphate, 500-750 parts of potassium humate, 5-10 parts of zinc sulfate, 300-500 parts of biochar and 10-20 parts of borax;
• wherein the water-retaining agent comprises following raw materials in parts by weight:
• 1000-1500 parts of polyacrylamide, 400-600 parts of methylallyl polyoxyethylene ether, 300-450 parts of 2-acrylamide-2-methylpropanesulfonic acid, 100-200 parts of carboxymethyl cellulose, 40-60 parts of ammonium persulfate, 2-3 parts of N, N′-methylene bisacrylamide, 300-500 parts of montmorillonite and 150-250 parts of kaolin, comprising following steps:
• S1, mixing the urea, the diammonium phosphate, the potassium sulfate, the ammonium sulfate, the potassium dihydrogen phosphate, the potassium humate, the zinc sulfate, the biochar and the borax, adding water, and stirring for dissolving to obtain a mixture A;
• S2, sieving the montmorillonite and the kaolin with a 400-mesh sieve, adding the water, fully stirring, adding the carboxymethyl cellulose, and performing an ultrasonic dispersion to obtain a soil colloid;
• S3, fully stirring the polyacrylamide, the methylallyl polyoxyethylene ether and the 2-acrylamide-2-methylpropanesulfonic acid, and adding the water for dissolving, then mixing with the soil colloid obtained in the S2, and carrying out the ultrasonic dispersion again to obtain a dispersion liquid;
• and
• S4, respectively adding ammonium persulfate dispersion and N, N′-methylene bisacrylamide solution into the dispersion liquid obtained in the S3 in a nitrogen environment, uniformly stirring at 60° C., adding the mixture A obtained in the S1, adding the clay to obtain a mixture B, then adding the water into the mixture B, uniformly stirring, granulating and drying to obtain the polymeric salt-tolerant and water-retaining fertilizer.