测深施氮对提高水稻产量和氮肥利用效率具有重要作用。然而测深施肥条件下，减少施氮次数和减少施氮量对水稻产量及氮素吸收利用影响的研究较少。本研究在测深施条件下，于2018和2019年分别设置了减少施氮次数(RTN)和减少施氮量(RNR)试验，测定了水稻产量及其构成因素、SPAD值、叶面积指数、干物质积累、氮素积累、氮肥利用效率相关指标，比较了各处理间上述指标的差异。结果发现相同施氮量条件下， RTN3 (70%基肥侧深施+30%穗肥)处理下南粳9108和南粳5718产量比常规施肥分别提高了9.64%和10.18%。品种和处理间SPAD值、LAI指数、干物质积累差异达到极显著水平。在2018和2019年，抽穗期氮素积累最高的为RTN3，其平均氮素积累量为11.33×10^-2 t hm^-2。相同施氮量下RTN3氮肥农学利用率、氮肥生理利用率、氮肥吸收利用率分别比其余处理提高了8.1%-21.28%、8.51%-41.76%、0.28%-14.52%。随着施氮量的降低，RNR各处理的SPAD、LAI、干物质积累、氮效率相关指标显著降低。侧深施肥下，减少氮肥施用次数和减少施氮量均可以使水稻高产高效，本研究将为测深施肥条件下水稻精确定量施肥提供重要的参考依据。

Land use practice significantly affects soil properties. Soil is a major sink for atmospheric carbon, and soil organic carbon (SOC) is considered as an essential indicator of soil quality. The objective of this study was to assess the effects of N and P applied to Suaeda salsa on biomass production, SOC concentration, labile organic carbon (LOC) concentration, SOC pool and carbon management index (CMI) as well as the effect of the land use practice on soil quality of coastal tidal lands in east coastal region of China. The study provided relevant references for coastal exploitation, tidal land management and related study in other countries and regions. The field experiment was laid out in a randomized complete block design, consisting of four N-fertilization rates (0 (N0), 60 (N1), 120 (N2) and 180 kg ha-1 (N3)), three P-fertilization rates (0 (P0), 70 (P1) and 105 kg ha-1 (P2)) and bare land without vegetation. N and P applied to S. salsa on coastal tidal lands significantly affected biomass production (above-ground biomass and roots), bulk density (ρb), available N and P, SOC, LOC, SOC pool and CMI. Using statistical analysis, significantly interactions in N and P were observed for biomass production and the dominant factor for S. salsa production was N in continuous 2-yr experiments. There were no significant interactions between N and P for SOC concentration, LOC concentration and SOC pool. However, significant interaction was obtained for CMI at the 0-20 cm depth and N played a dominant role in the variation of CMI. There were significant improvements for soil measured attributes and parameters, which suggested that increasing the rates of N and P significantly decreased ρb at the 0-20 cm depth and increased available N and P, SOC, LOC, SOC pool as well as CMI at both the 0-20 and 20-40 cm depth, respectively. By correlation analysis, there were significantly positive correlations between biomass (aboveground biomass and roots) and SOC as well as LOC in 2010 and 2011 across all soil depth, respectively. The treatment with N at 180 kg ha-1 and P at 105 kg ha-1 was superior to the other treatments. The results from the 2-yr continuous experiments indicated that, in short-term, there were a few accumulation of SOC and LOC concentrations by means of N and P application to S. salsa, whereas in the long run, S. salsa with N and P application was recommended for coastal tidal lands because of its great potential of carbon sequestration, improvements of soil nutrition status and promotion of soil quality.

The aim of this paper was to research the spatio-temporal changes in total soluble salt content (TS) in a typical arid region of South Xinjiang, China, where the climate is arid and soil salinization happens easily. The total soluble salt content was interpreted by measurements made in the horizontal mode with EM38 and EM31. The electromagnetic induction (EM) surveys were made three times with the apparent soil electrical conductivity (ECa) measurements taken at 3 873 locations in Nov. 2008, 4807 locations in Apr. 2009 and 6 324 locations in Nov. 2009, respectively. For interpreting the ECa measurements into total soluble salt content, calibtion sites were needed for EM survey of each time, e.g., 66 sites were selected in Nov. 2008 to measure ECa, and soils-core samples were taken by different depth layers of 0-10, 10-20 and 20-40 cm at the same time. On every time duplicate samples were taken at five sites to allevaite the local-scale variability, and soil temperatures in different layers through the profiles were also measured. Factors including TS, pH, water content, bulk density were analyzed by lab experiments. ECa calibration equations were obtained by linear regression analysis, which indicated that soil salinity was one primary concern to ECa with a determination coefficient of 0.792 in 0-10 cm layer, 0.711 in 10-20 cm layer and 0.544 in 20-40 cm layer, respectively. The maps of spatial distribution were predicted by Kriging interpolation, which showed that the high soil salinity was located near the drainage canal, which validated the trend effect caused by the irrigation canal and the drainage canal. And by comparing the soil salinity in different layers, the soluble salt accumulated to the top soil surface only in the area where the soil salinization was serious, and in the other areas, the soil salinity trended to increase from the top soil surface to 40 cm depth. Temporal changes showed that the soil salinity in November was higher than that in April, and the soil salinization trended to aggravate, especially in the top soil layer of 0- 10 cm.