Responses of Crop Yield, Soil Fertility, and Heavy Metals to Spent Mushroom Residues Application

Abstract

Waste mushroom residues are often returned to fields as organic amendments. Here, we estimated the effects of the continuous applications of different spent mushroom substrates for 2 years on crop yields, soil nutrients, and heavy metals in paddy fields. The study comprised seven treatments: no fertilization (CK) and mineral NPK fertilizer (CF), as well as NPK fertilizer combined with Enoki mushroom residue (EMR50), Oyster mushroom residue (OMR50), Auricularia polytricha mushroom residue (APR50), Shiitake mushroom residue (SMR50), and Agaricus bisporus residue (ABR50). The grain yield was highest under the APR50 treatment. The short-term application of waste mushroom residue significantly increased SOC, TN, TP, and TK content relative to the CK treatment. The SOC, TP, and TK were highest under ABR50. Both total Cr and Cd contents were highest under CF treatment. The highest cumulative ecological risk was observed under OMR50 treatment. In addition, crop yield was positively correlated with SOC, TN, TP, and TP. Our results highlight that further research and innovation are needed to optimize the benefits and overcome the challenges of mushroom residue application.

Keywords: agro-ecosystems; crop yield; heavy metal; mushroom residue; soil fertility.

Figure 1

Effect of different waste mushroom residue application on soil fertility. (a) Effect of different waste mushroom residue application on SOC. (b) Effect of different waste mushroom residue application on SOC. (c) Effect of different waste mushroom residue application on TP. (d) Effect of different waste mushroom residue application on TK. SOC, TN, TP, and TK indicate soil organic carbon content, total nitrogen, total phosphorus, and total potassium, respectively. CK, CF, EMR50, OMR50, APR50, SMR50, and ABR50 indicate no fertilization, mineral NPK fertilizers, and NPK fertilizer combined with Enoki mushroom residue, Oyster mushroom residue, Auricularia polytricha mushroom residue, Shiitake mushroom residue, and Agaricus bisporus residue. Different lowercase letters indicate significant differences among treatments (p < 0.05).

Figure 2

Effect of mushroom residue application on heavy metal contents and the cumulative risk. (a) Effect of different waste mushroom residue application on Cr. (b) Effect of different waste mushroom residue application on Cd. (c) Effect of different waste mushroom residue application on Pb. (d) Effect of different waste mushroom residue application on RI index. Cr, Cd, Pb, and RI indicate chromium, cadmium, lead, and potential ecological risk. CK, CF, EMR50, OMR50, APR50 SMR50, and ABR50 indicate no fertilization, mineral NPK fertilizers, and NPK fertilizer combined with Enoki mushroom residue, Oyster mushroom residue, Auricularia polytricha mushroom residue, Shiitake mushroom residue, and Agaricus bisporus residue. Different lowercase letters indicate significant differences among treatments (p < 0.05).

Figure 3

Relationships between soil nutrients and crop yield and heavy metals. The black circles indicate the observed data. The red line indicates the fitted line. * p < 0.05, ** p < 0.01, *** p < 0.001. The red square represents a strong tendency towards statistical significance (p = 0.051). Yield, TN, TP, TK, SOC, Cr, Cd, and Pb indicate crop yield, total nitrogen, total phosphorus, total potassium, soil organic carbon, chromium, cadmium, and lead, respectively.

Figure 4

Schematic diagram of field fertilization management.