Phosphorus acquisition by barley (Hordeum vulgare L.) at suboptimal soil temperature
We studied the effects of soil temperature (8 ºC and 15 ºC) on barley growth, barley phosphorus (P) uptake and soil P solubility. Barley was grown in a pot experiment in two soils with different P fertilization histories for 22 years. The availability of P was estimated by using 33P-labeled fertilizer and calculating L-values. After cultivation for 22 years at ambient soil temperature without P fertilization (-P), soil L-value had decreased compared to soil that received annual P fertilization (P+). Low soil temperature further reduced the L-values, more in the -P soil than in the +P soil. Our results demonstrated that P fertilization can only partially ameliorate poor growth at low soil temperatures. Thus, applying ample fertilization to compensate for poor growth at low soil temperatures would increase the P content and solubility in the soil, but plant uptake would remain inhibited by cold.