Comparison of Contribution of Wheat Ionic Uptake to Soil Acidification Under Long-term Different Fertilization

The long-term unreasonable fertilization leads to serious soil acidification in agricultural production. In addition to nitrification and nitrate leaching, the uptake of cations by plants is also an important source of soil acidity. In this study, the effects of long-term different fertilization on the absorption of anion and cation in wheat were studied at the long-term location experiment field of the Red Soil Experimental Station in Qiyang, Hunan Province, which has a history of 25 years. The results showed that long-term application of chemical nitrogen fertilizer significantly decreased soil pH and affected the biomass of wheat. On the contrary, organic fertilizer could alleviate the acidification process of soil and increase the biomass of wheat. The order of the total amounts of proton produced by wheat in the unit soil area which is considered as potential acidification ability of plant was M>NPKM>PK>NPK>CK>NP>NK. There was a significant positive correlation between total amount of proton and total biomass of wheat. In addition, soil pH and available phosphorus content were the main factors affecting wheat shoot biomass. Therefore, in the long-term fertilization of farmland soil, the contribution of crops to soil acidification decreased along with the acidification process, and the main reason was that soil pH and effective phosphorus reduction limited the crop biomass.