In coastal regions, Bohai Gulf is one of the most affected areas by salinization. To study the effects of mocrosprinkler irrigation on the characteristics of highly saline sandy loam soil (ECe (saturated paste extract)=22.3 dS m^–1; SAR (sodium adsorption ratio)=49.0) of North China, a laboratory experiment was conducted. Five water application intensity (WAI) treatments (1.7, 3.1, 5.3, 8.8, and 10.1 mm h^–1), five irrigation amount (IA) treatments (148, 168, 184, 201, and 223 mm) and three time periods of water redistribution (0, 24 and 48 h) were employed in the study. A compounding microsprinkler system was used for the WAI treatments, and a single microsprinkler was used for the IA treatments. The results indicated that, as soil depth increased, soil water content (θ) increased and then slightly decreased; with WAI and IA consistently increasing, the relatively moist region expanded and the average θ increased. Meanwhile, soil ECe increased as soil depth increased, and the zone with low soil salinity expanded as WAI and IA increased. Although the reduction of the average SAR was smaller than that of the average electrical conductivity of the ECe, these variables decreased in similar fashion as WAI and IA increased under microsprinkler irrigation. The average pH decreased as soil depth increased. Longer time periods of water redistribution led to lower salinity and slight expansion of the SAR zone. Considering the effects of leached salts in coastal saline soils, greater WAI and IA values are more advantageous under unsaturated flow conditions, as they cause better water movement in the soil. After leaching due to microsprinkler irrigation, highly saline soil gradually changes to moderately saline soil. The results provide theoretical and technological guidance for the salt leaching and landscaping of highly saline coastal environments.

Laboratory and field experiments were conducted to investigate the effects of water application intensity (WAI) on soil salinity management and the growth of Festuca arundinacea (festuca) under three stages of water and salt management strategies using microsprinkler irrigation in Hebei Province, North China. The soil water content (è) and salinity of homogeneous coastal saline soils were evaluated under different water application intensities in the laboratory experiment. The results indicated that the WAI of microsprinkler irrigation influenced the è, electrical conductivity (ECe) and pH of saline soils. As the WAI increased, the average values of è and ECe in the 0–40 cm profile also increased, while their average values in the 40–60 cm profile decreased. The pH value also slightly decreased as depth increased, but no significant differences were observed between the different treatments. The time periods of the water redistribution treatments had no obvious effects. Based on the results for è, ECe and pH, a smaller WAI was more desirable. The field experiment was conducted after being considered the results of the technical parameter experiment and evaporation, wind and leaching duration. The field experiment included three stages of water and salt regulation, based on three soil matric potentials (SMP), in which the SMP at a 20-cm depth below the surface was used to trigger irrigation. The results showed that the microsprinkler irrigation created an appropriate environment for festuca growth through the three stages of water and salt regulation. The low-salinity conditions that occurred at 0–10 cm depth during the first stage (−5 kPa) continued to expand through the next two stages. The average pH value was less than 8.5. The tiller number of festuca increased as SMP decreased from the first stage to the third stage. After the three stages of water and salt regulation, the highly saline soil gradually changed to a low-saline soil. Overall, based on the salt desalinization, the microsprinkler irrigation and three stages of water and salt regulation could be successfully used to cultivate plants for the reclamation of coastal saline land in North China.

In this study, nano-capsules of lansiumamide B (NCLB) was prepared by the microemulsion polymerization method to improve the nematicidal efficacy of lansiumamide B (LB). An optimal formulation was gained by orthogonal experiment design based on the encapsulation efficiency (En, %) value. The optimized NCLB were spherical and uniform under transmission electron microscopy (TEM). The mean particle size, zeta potential and En were (38.50±0.64) nm, (-70.5±0.76) mV and (95.13±1.16)%, respectively. The release profile indicated that the accumulated release of LB in NCLB reached up to 82% within 96 h. Effects of NCLB against Bursaphelenehus xylophilus and J2 of Meloidogyne incognita were reported in this paper. The nematicidal activity of NCLB has been remarkably increased, with LC50 values of 2.1407 mg L-1 and 19.3608 mg L-1, respectively, at 24 h after treatment. The disease progression and the average number of root knots of Ipomoea aquatica were 1.50 and 7.25, respectively, in the treatment of NCLB, at concentration of 200 mg L-1, significantly lower than the treatment of LB and ethoprophos. Compared to control, the treatments of NCLB, LB and ethoprophos leaded the disease progression to drop 68.42, 36.84 and 26.32%, respectively, and caused the average number of root knots to fall 83.94, 78.03 and 63.66%. These results suggested that NCLB, as a novel nematicides formulation, performed more efficient and longer effective maintenance against plant parasitic nematodes.

This study aimed to compare the effects of two types of drip irrigation line design on cotton yield, water use, and net returns. The experiments were carried out in the arid region of Xinjiang, Northwest China, during 2009-2010 growing years. The two types of lateral placement are commonly used by the local farmers in the area: double lines (two laterals controlling four rows) and single line designs (one lateral controlling four rows). The results indicated that less irrigation water was applied by single line compared with double lines design. This implies that more irrigation water could be saved using single line, by reducing the water consumption of cotton. The emergence rates for double lines were 2 and 6% higher than those for single line design in 2009 and 2010. The seed cotton yields for double lines design were 5.76 and 6.41 Mg ha-1 which were 13 and 9% higher than for single line design in 2009 and 2010, respectively. Single lines could however lower the investment cost compared to double lines, which produced 10 and 7% more net income in 2009 and 2010, respectively. By contrast, the double lines was more profitable and suitable for the farmers in Northwest China than single line design.