大气温度对土壤养分迁移和春小麦干物质积累的效应

Effects of Atmospheric Temperature on Soil Nutrient Movement and Dry Matter Accumulation of Spring Wheat

试验设 2 2℃和 2 8℃两种温度水平 ,并设 N1 P1 K1 ,N1 P2 K2 ,N2 P1 K1 ,N2 P2 K2 4个肥料水平。结果表明 ,高氮时 ,2 8℃时春小麦地上部干物重 ,根干物重 ,干物质总量和根冠比率比 2 2℃时平均分别下降 2 7% ,4 2 % ,30 % ,2 0 % ,根系氮、磷、钾浓度和小麦对氮、磷、钾的吸收较 2 2℃时也低。根际土壤 p H约比土体 p H降低 0 .2 ,温度对根际土壤 p H值会产生影响 ,但不同氮肥用量处理表现不同 ,低氮时 ,2 2℃时根际土壤 p H值比原土降低 0 .3,而 2 8℃时根际土壤 p H值并不降低 ;高氮时 ,2 2℃和 2 8℃根际土壤 p H值均比原土降低 ,但 2 8℃时降低更多。高氮 2 8℃温度处理根际土壤 NO- 3 -N含量远比土体高 ,2 8℃时根际土壤 NO- 3 -N含量比 2 2℃时要高 ,氮肥用量高时更为明显。根际土壤速效 P含量比土体速效磷低 ,2 8℃温度时根际土壤速效磷量较高。

Spring wheat (Triticum aestivum L.) was treated with two levels of temperature (22℃ and 28℃) and four fertilizer levels (N 1P 1K 1, N 1P 2K 2, N 2P 1K 1, N 2P 2K 2). The study showed with high N treatment, shoot, root and total dry mass weight and root/shoot ratio at 28℃ was lower than that at 22℃, with an average reduction of 27%, 42%, 30%, 20%,respectively; root N, P, K concentration and N, P, K uptake of spring wheat at 28℃ were lower than that at 22℃, too. Rhizosphere soil pH decreased 0.2 pH compared with bulk soil pH. Temperature affected rhizosphere soil pH, but pH varied differently with different N treatments. With low N treatment, rhizosphere soil pH decreased 0.3 pH compared with soil pH at 22℃, no change at 28℃. With high N treatment, rhizosphere soil pH decreased at both 22℃ and 28℃, even more at 28℃. Rhizosphere soil nitrate (NO - 3-N) contents are much higher than bulk soil NO - 3-N under high N and temperature treatment. Rhizosphere soil NO - 3-Ν contents at 28℃ are higher than that at 22℃, even significant difference with high N treatment. Rhizosphere soil available P contents are lower than bulk soil P, but rhizosphere soil available P contents are higher with rising temperature,