This study investigated the effects of salinity stress at different growth stages on the growth, yield, fruit quality, and water-use efficiency (WUE) of tomato (Solanum lycopersicum) plants cultivated under soilless conditions. Six different growth stages were exposed to the same salinity stress treatments using a completely randomized design, with three pots (six plants) per treatment. It was found that short-term (<21 days) salinity stress during any of the growth stages did not affect tomato growth or WUE, and during the vegetative stage did not affect yield. Salinity stress during the flowering and fruiting stages caused a reduction in tomato yield, which was due to a reduction in the number of fruit produced rather than the fruit size. However, salt exposure at the fruiting stage also improved fruit quality. The effect of salinity stress on the yield and fruit quality of the frontal and later truss depended on the developmental stage of the truss at the time when the stress occurred.

In the cold zone of China, winter is cold and long and has a short duration of sunshine. Unheated earthen‐wall solar greenhouses are used for tomato production in winter in this region. This was an experimental investigation of different organic mulching materials (newspaper, bran, and grass) on the soil temperature, soil moisture, tomato yield, fruit quality, and water use efficiency. Organic mulching variously improved soil temperature, soil moisture, water use efficiency, and tomato yield, which is very important for greenhouse winter cultivation in this cold zone. Organic mulching regulated the soil temperature, with daily soil temperature ranges of bran, newspaper, and grass treatments being 1.6, 1.9, and 2.1°C lower than for bare land, respectively. Compared to bare land, newspaper mulching had little effect on soil temperature and fruit quality, but increased soil moisture (14.1%) and water use efficiency (WUE: WUE_b, 31.3%; WUE_y, 30.6%), and greatly increased yield (81.8%) and biomass (82.7%); bran mulching greatly increased soil temperature, moisture (16%), and WUE (WUE_b, 60.1%; WUE_y, 44.3%) and increased biomass (30.2%) and yield (17.3%); grass mulching greatly increased soil temperature and moisture (20.9%) and increased biomass (17.9%), yield (11.2%), and WUE (WUE_b, 20.5%; WUE_y, 13.6%). In addition, organic mulching had a good water retention effect on soil layer above 30 cm. The total soil water consumption during tomato growth was in the following order: newspaper (103 mm) > bare (74 mm) > grass (73 mm) > bran (60 mm). Soil water consumption mainly occurred in the 0‐ to 10‐cm soil layers.

The study aims to find the properties of three organic mulch varieties and their effects on soil moisture and crop growth. Three organic mulches: newspaper, grass, and bran were selected as the research objects, and were analyzed through double-ring infiltration and water loss tests so that water permeability and water-holding capacity of the three mulching materials could be figured out. The results showed the descending order of the three mulching treatments and non-treatment by the infiltration rate of the soil: newspaper > bare ground > grass > bran. In terms of the water-holding capacity, the three organic mulches can be ranked from high to low as newspaper, grass, and bran; by the cumulative water loss as newspaper, grass, and bran; and by water-retention capacity as bran, grass, and newspaper, respectively. By conducting regression analysis, it is found that the water-holding capacity of the mulches is related to water immersion time and the amount of water absorbed and that there is a significant logarithmic relationship between the amount of water loss and water losing time. The fitting results of the three mulches are good. Besides, a power-function relationship exists between water absorption rate and immersion time, and between water loss rate and water loss time. The water infiltration of the soil under the newspaper mulching treatment is the best, as the newspaper can help to improve soil moisture and weaken surface runoff under flood irrigation and heavy rain. Bran possesses the strongest capacity for water retention, which is beneficial to soil moisture retention in areas where sprinkler irrigation, drip irrigation, and light to moderate rain prevail. The research results can provide a basis for improving the moisture-utilization efficiency in farmlands by using organic mulches.

Water resources are scarce in the Northeastern Loess Plateau, and water cellar water (WCW) is a vital water resource available in the vast rural areas of the region. The quality of WCW was assessed by principal component analysis (PCA) and Nemerow’s pollution index (NPI) for different rainfall catchment areas, depths, and storage times. Eleven indicators were measured, including pH, electrical conductivity (EC), F⁻, Cl⁻, NO₃⁻, SO₄²⁻, Na⁺, NH₄⁺, Ca²⁺, Mg²⁺, and K⁺. The results show that the tap water quality in the rural areas of the Northeastern Loess Plateau is above the second level and meets the drinking water standard (DWS), which is similar to the tap water quality in the region. The main component score of water quality from tile roof + cement ground (I) is 0.32, and the Nemero index is 0.41; the principal component score of water quality from cement ground (I) is 0.45, and the Nemero index is 0.29; the principal component score of water quality from trampled land (I) is 0.59, and the Nemero index is 0.44; the principal component score of water quality from tile roof + trampled land (II) is 1.87, and the Nemero index is 1.10. The rainwater harvesting catchment area of tile roof + cement ground (I) ensured the highest water quality, followed by cement ground (I), trampled ground (I), and tile roof + trampled ground (II). The water quality of the catchment area for artificially collected rainwater (roof tile surface, cement ground, etc.) was better than that of the original soil (trampled ground). The highest water quality was found at a storage time of 1 year (I), followed by 2.5 years (I), and 2 months (II). A depth of 4 m (I) contributed to the highest water quality, followed by 2 m (II), 3 m (II), and 1 m (II). Water quality improved with the increasing depth of WCW. The rainfall and WCW in the area were weakly alkaline, and the groundwater was contaminated with NO₃⁻. PCA’s water quality assessment results were similar to the NPI method, indicating that both methods can be used in combination for unconventional water quality assessment.

This study was conducted to investigate the effects of salinity stress and flower number on growth, yield, water use efficiency (WUE), and fruit quality of cherry tomatoes cultivated under soilless conditions. The experiment was conducted in a plastic house (5-m wide × 11-m long) located in Gifu University. The seedlings were transplanted in a randomized complete block design with six plants per treatment (NT1 and ST1 were with four plants), giving a total of 44 plants in 22 pots (two plants per pot). Two different salinity levels [no-salinity and salinity with electrical conductivity: 0.8 and 3.0 dS m⁻¹, respectively] and four flower number treatments (8, 13, 18, and free per truss) were investigated in the experiment. The results showed that salinity stress negatively affected tomato growth, yield, and marketable yield, but improved tomato fruit quality. The number of flowers had no effect on tomato growth variables and WUE, but the yield significantly increased with increasing flower number. However, the fruit quality was decreased with increased flower number. A reasonable control for fruit load can increase marketable yield in commercial cultivation. Under salinity stress conditions, properly increasing the number of flowers can avoid yield reduction.

This was an experimental investigation of the combined treatments of salinity (SAL) stress and fruit thinning (FT) on the growth, yield, fruit quality, and water use efficiency (WUE) of tomatoes with non-soil cultivation. The experiment was carried out in a plastic tunnel, Japan. Tomato (Solanum lycopersicum) cv. Momotaro seedlings were transplanted in a randomized complete block (RCB) manner with six plants/treatment, and an overall 36 plants in 18 pots (2 plants/pot). The experiment involved varying SAL treatment (no-SAL, moderate SAL, and serious SAL, with electroconductivity of 0.8, 3.0, and 4.5 dS m⁻¹, separately) and FT treatment (NT: no thinning and 3FT: three-fruit treatment). The tomato growth, yield, and WUE were significantly suppressed with increasing SAL. In comparison, FT treatment had less effect on tomato growth and water consumption. Either SAL stress or FT treatment significantly improved fruit quality. The combined treatment proved better than single treatment of either SAL stress or FT, avoided the subsize fruit following SAL stress treatment, reduced fruit cracking found with FT treatment, and greatly improved fruit quality. The SAL thresholds of WUEs in relation to biomass, yield, and marketable yield were approximately 3.0 dS m⁻¹ under these soilless conditions. Path analysis showed that biomass and water consumption were important indexes affecting yield. Logistic equation fitting showed that SAL stress tended to inhibit and delay plant growth; however, FT tended to advance and shorten the period of plant growth.