Surface Drainage and Mulching Drip-Irrigated Tomatoes Reduces Soil Salinity and Improves Fruit Yield.

A study on the effects of mulched drip irrigation combined with surface drainage on saline soil and tomatoes was conducted in coastal areas of eastern China, where the crops are subjected to excessive salt. The treatments contained three irrigation rates-200, 250 and 300 m3/ha-and three drain ditch depths-10, 20 and 30 cm. The contents of soil salinity, organic matter and available nutrient were observed, and the tomato plant height, stem diameter and leaf area index during different growth periods were recorded. Results showed that the total removal rate of salt from soil at a 0-1 m depth was 8.7-13.2% for the three drainages. Compared with the control, the treatments increased the content of available N (by 12.1-47.1%) and available K (by 5.0-21.9%) in the soils inside the mulch and decreased the content of available N (by 3.4-22.1%) and available K (by 7.5-16.4%) in the soils outside the mulch. For tomatoes, the plant height and the stem diameter was increased significantly by the irrigations but was not significantly affected by the drainages, and the leaf area index was increased by 0.39~1.76, 1.10~2.90 and 2.80~6.86 respectively in corresponding to the seedling, flowering and fruit-set stage. Moreover, yield-increase rates of 7.9-27.6% were found for the treatments compared to the control with a similar amount of applied water

Effect of Different Water Stress on Growth Index and Yield of Semi-Late Rice

The aim of this research is to find out the effects of different degrees of drought stress on the growth index and yield of semi-late rice. In this experiment, a pot experiment was conducted with hybrid Tian-you-hua-zhan rice as material. Intermittent irrigation was used as control (CK) at the tillering stage, booting stage, heading stage, and milk stage. Three water stress gradients of light drought (70% saturated moisture content), medium drought (60% saturated moisture content), and severe drought (50% saturated moisture content) were set to monitor the soil moisture content. The plant height, number of tillers, leaf area, and chlorophyll content under different water gradients at different growth stages were measured, and the effects of different water stress treatments at different growth stages on rice growth index, yield, and its components were analyzed. The results showed that the inhibition of the plant height at the jointing and booting stages was the most significant; moreover, the number of tillers and leaf area decreased most significantly at the tillering stage, and the heading and flowering stages had the greatest effect on chlorophyll synthesis. As far as yield is concerned, the most sensitive stages are the heading and flowering stages. Different stress treatments reduced the effective panicle number, 1000-grain weight, and seed setting rate of rice, and reduced the yield by 27.57%, 44.23%, and 46.32% respectively, compared with the normal control. The correlation analysis showed that the correlation degree of affecting yield from large to small was 1000-grain weight, seed setting rate, and effective panicle. Therefore, ensuring water supply at the heading and flowering stage can effectively improve the 1000-grain weight, effective panicle, and seed setting rate, and increase the rice yield and water use efficiency

The arrangement of plants and the locations of soil samples.

<p>The arrangement of plants and the locations of soil samples.</p

Plant height, stem diameter and leaf area index of tomato under different treatments.

<p>Plant height, stem diameter and leaf area index of tomato under different treatments.</p

Experimental design.

<p>Experimental design.</p

The date of irrigation, drainage and soil sampling.

<p>The date of irrigation, drainage and soil sampling.</p

The content of available N (a), P (b) and K (c) in soil at a 0-20-cm depth with different treatments.

<p>(SIM and SOM represent the sampling location inside and outside the mulch, respectively. Means followed by the same letter (a, b, c) do not differ significantly at the 0.05 level, according to Duncan’s multiple range test. I and D represent quotas of irrigation and depths of drain ditch, respectively. *, **and ns indicate that the experimental treatment has a significant (at 0.05 level) effect, an extremely significant (at 0.01 level) effect, and no significant effect on the available nutrient, respectively.)</p

The tomato yield with different treatments.

<p>(The values of tomato yield are the means of three replications. Means followed by the same letter (a, b, c) do not differ significantly at the 0.05 level, according to Duncan’s multiple range test. I and D represent quotas of irrigation and depths of drain ditch, respectively. **and ns represent indicate the experimental treatment has an extremely significant (at 0.01 level) effect and no significant effect on the tomato yield, respectively.)</p

Variations of soil salinity with different treatments.

<p>(SIM and SOM represent the sampling location inside and outside the mulch, respectively.). DAT represented days after transplanted, Seedlings were transplanted into the fields on June 10.</p

The decreasing rate of soil salt with different treatments.

<p>(SIM and SOM represent the sampling location inside and outside the mulch, respectively. The rate was calculated from Jun. 10 to Sept. 21.The values of the decreasing rate are the means of three replications. In the same sampling location (SIM or SOM), the means followed by the same letter (a, b, c) do not differ significantly at the 0.05 level, according to Duncan’s multiple range test. I and D represent quotas of irrigation and depths of drain ditch, respectively. *, **and ns indicate that the experimental treatment has a significant (at 0.05 level) effect, an extremely significant (at 0.01 level) effect and no significant effect on the decreasing rate, respectively.)</p