| It is of profound importance to study effects of rotation with legumes and N input levels on yield and
grains nutrient contents of wheat in dryland of the Loess Plateau, where people are in trouble of malnutrition and soils are condemned to be deficient in available nutritional elements. A field experiment was carried out to study the effects of ro-tation with legumes on wheat yield and nutrient contents of wheat grains with four rotation types (fallow wheat，mung bean-wheat，soybean-wheat, and qiubean (local bean)- wheat ) at four N input levelsof 0, 108， 135 and 162 kg/ hm2 on dryland of the Loess Plateau. Obtained results showed that wheat yield was significantly decreased by 9.7%~ 26.6% due to water deficiency after rotation with legumes. By comparison with fallw treatment， the amount of nutrients ab-sorbed of wheat grains decreased significantly or slightly. Specifically， the decreased amount of nutrients absorbed of wheat grains was from10.5% to 29. 3% after rotation with mungbean，which decreased the most of three rotation types,
and the second was rotation with soybean， the decreased amount of nutrients absorbed was from 3. 1% to 12. 8%, whereas after rotation with qiubean (local bean)，the decrease was merely from 0.98% to 11.7%，which was the least among three rotation types. However, by rotation with legumes，the average contents of Zn, P, K, Ca and Mg of wheat grains were increased by 22.0%, 18.5%, 8.8%, 7. 9% and 7. 8%, respectively. Among three N input levels, 108 kg N/hm2(80% of local routine N rates) showed higher wheat yields. With the increasing of N input, the contents and the amount of absorbed N, S, Ca, Fe， Cu and Zn of wheat grains tended to be increased, on the contrary， P contents and P-absorbed amount were decreased, and Mn contents decreased but Mn absorbed amount was increased, whereas K and Mg were not significantly influenced. |