The invention discloses a method for cultivating oil sunflowers in
saline-alkali lands by means of
brackish water underground
drip irrigation. The method has the advantages that structures for perfectly regulating and controlling water, fertilizers and air for root zones of the oil sunflowers are proposed and constructed, micro-
topography structures, underground
drip irrigation and
plastic film mulching technologies are coupled with one another, accordingly, effects of conserving soil
moisture and reducing salt can be realized to the greatest extent, and a relatively good soil environment canbe provided for growth and development of crops; thresholds for perfectly regulating and controlling the water, the fertilizers and the air for underground
drip irrigation for the oil sunflowers in the
saline-alkali lands are proposed, appropriate quantities of water and fertilizers and dissolved
oxygen with suitable concentration are directly delivered to positions near root systems of the cropsin underground drip
irrigation modes, accordingly, soil in the main root zones of the oil sunflowers can always keep in the optimal water and
nutrient states, and the optimal
oxygen content of the soil in the main root zones of the oil sunflowers always can be kept; reasonable
saline-alkali regulation and control processes are further proposed, salinization and alkalinization improvement can be carried out by the aid of suitable salt washing water volumes and reasonable desulfurization
gypsum application amounts, the problem of salification of drip
irrigation soil in existing saline-alkali lands can be solved, accordingly, the alkalization degree of the soil can be effectively lowered, and the purpose of improving the soil can be achieved.