| Abstract:To explore the effect of phosphorus(P) application rate on wolfberry yield ,P absorption,P profit and loss in soil ,an experiment under treatments of 0(P0),133(P133),267(P267),400(P400),534(P534) and P667(traditional P rate of P2O5 667 kg/hm) was conducted at Nuomuhong Farm in Qinghai province from 2019 to 2020. Soil available-P accumulation,plant P accumulation and soil apparent P profit and loss were calculated. With increase of P application rate,wolfberry yield increased firstly,and then decreased. The yield was highest under treatment of P534,34.7% and 38.2% higher than control treatment(P0). In two years,the highest net income was achieved under P534treatment,which was 143 315 and 162 795 yuan/hm ,respectively,and increased by 12.5% and 3.6% compared with P667. The P application significantly increased the plant P accumulation. P534had the highest plant P accumulation,which was 69.7% and 7.0% higher than that of P0 and P667. The variation of soil available-P concentrated in 0-60 cm soil and the soil available-P accumulation increased with increase of P application rate. In 2019 and 2020,P in soil was in deficit at 133 kg/hm P fertilizer,but surplus at 267-667 kg/hm. The profit of soil apparent P in P534was 135.1 and 87.0 kg/hm,respectively in the two years,which decreased by 31.0% and 43.8% compared with P667. There was a significant positive correlation between P application rate and soil apparent P profit and loss(P<0.01),which increased by 41.6 and 35.6 kg/hm with the increase of P application rate of 100 kg/hm.Soil P was in balance when P rate was 198.3 and 245.7 kg/hm respectively in two years. Comprehensively,the recommended P fertilizer rate(P2O5) was 534 kg/hm in wolfberry orchards with middle and high fertility in Qaidam. |
