水稻旱直播氮肥施用量与种植密度配比的研究

通过控制纯氮施用量和播种的基本苗数，研究北方地区水稻早直播的最佳肥密配比．试验结果表明，增施氮肥对改善旱直播水稻的生长性状、提高分蘖数和成穗率、促进二次枝梗分化、增加每穗结实率和促进产量都有显著的提高作用，但氮肥施用量有一定的阈值．在施纯氮180kg／hm^2的条件下，各产量构成要素性状表现最优．种植密度对株高、枝梗分化、结实率、分蘖的影响较小．肥料与密度的最优配比为纯氮180kg／hm^2，基本苗200万株／hm^2，其产量最高，达6270kg／hm^2．

Best match for nitrogen fertilizer levels and planting densities in dry direct seeding rice

The best match for nitrogen fertilizer and planting density was provided by controlling the levels of nitrogen fertilizer and basis seedling number of rice. The results showed that increasing nitrogen fertilizer level had remarkable effects on improving the growth characteristics, adding the numbers of tiller and rate of earing, and increasing the numbers of secondary branches and the rate of maturity when the amount of nitrogen was less than a certain limitation of nitrogen. If fertilized nitrogen 180 kg/hm^2, these various characteristics of the yield factors were best. It was negligible for the planting density affecting the height of rice plant, development of branch, rate of maturity and numbers of tiller. The best match for nitrogen and planting density was pure nitrogen 180 kg and the basis seedling of rice was 2 million per hectare, and the highest yield of rice was 6 270 kg/hm^2.