Movement and utilization of water and nutrient under different irrigation patterns

We conducted an experiment to determine the effect of different patterns of irrigation and fertilization on: (i) the distribution of nitrate and water in the soil profile and (ii) irrigation efficiency and the recovery of applied fertilizer. Micro-field trials were conducted using rain shelters to control water input. Maize Zea Mays L. cultivar: Hudan 4) was used as a test crop. The experiment consisted of two irrigation methods. One is alternate furrow irrigation method in which irrigation water was applied to one row and fertilizer was applied to the adjoining row at the same time. The other one is traditional method. In this method, water and fertilizer were both applied to the same row. Two water rates (450 m3/ha and 900 m3/ha) were set up and soil water and nitrate contents from 0-200 cm in the soil profile were determined in this experiment. Results indicated that there was a water potential difference between rows in the alternate (furrow) irrigation method when the rate of irrigation water was 450 m3/ha. So do the nitrate content. However, there was no significant difference on the water potential between rows when 900 m3/ha water was used. The low concentration of (nitrate) from 0-180 cm in the 900 m3/ha treatment indicated that nitrate was leached out. After maize harvest, the amount of available nitrate in the soil in the alternate furrow irrigation treatment was higher than that in the traditional (irrigation) treatment. However, the soil water content was less in the alternate furrow irrigation treatment compared to the traditional treatment. Grain yield in the alternate furrow irrigation treatment with 450 m3/ha of irrigation water was nearly equal to that of the traditional irrigation method under 900 m3/ha. This indicates that half irrigation water could be saved when the alternate furrow irrigation treatment was used without any yield reduction. Irrigation efficiency and the (recovery) of (fertilizer) in the alternate furrow irrigation method were higher than that of traditional model when the amount of irrigation water was 450 m3/ha. Evaporation was significantly decreased when the soil was mulched with wheat straw, moreover, the use of straw mulch is also beneficial to nutrient uptake. Nevertheless maize yield was not affected significantly by the mulch treatment. In conclusion, the alternate furrow irrigation method combined with the application of irrigation water at the rate of 450 m3/ha is appropriate for semi-humid areas. Straw mulch is of great advantage of water saving.