Yu ZhenWen

Effects of Supplemental Irrigation Based on Testing Soil Moisture on Dry Matter Accumulation and Distribution and Water Use Efficiency in Winter Wheat

Abstract Water shortage is a serious problem threatening sustainable development of agriculture in the North China Plain, where winter wheat ( Triticum aestivum L.) is the largest water-consuming crop. The objective of this study was to optimize irrigation scheme for high yield and high water use efficiency (WUE) in wheat, on the basis of Jimai 22, a representative cultivar in production. In the field experiments conducted in 2007–2008 and 2008–2009 growing seasons, unfixed amount of water was supplied at sowing, jointing, and anthesis stages to adjust the soil moisture into a controlled ladder. For example, the relative soil moisture contents in the W0 treatment were 80% at sowing, 65% at jointing, and 65% at anthesis; in the W1 treatment, they were 80%, 70%, and 70%, respectively; analogically, they were 80%, 80%, and 80% in the W2 treatment and 90%, 80%, and 80% in the W3 treatment. These results showed that the amount of dry matter accumulation at maturity was the lowest in the W0 treatment and the highest in the W1 treatment. The grain dry matter ratio was significantly higher in W1 than in W2 and W3. After anthesis, the dry matters in vegetative organs began to drain into grains, and the translocation amount and ratio were both ranked as W0 > W3 > W2 > W1, and the contribution of dry matter accumulation to grains was ranked as W1 > W2 > W3 > W0. Under the W1 condition, the filling rate and net photosynthetic rate maintained a relatively high level at the end of filling stage, which was favorable for increasing accumulation and distribution ratio of dry matter and grain weight at maturity. The WUE was higher in W0 than in other treatments. However, the grain yield was the lowest in treatment W0. In both growing seasons, the grain yield, irrigation water use efficiency (WUE I ), precipitation use efficiency (WUE P ), and irrigation benefit (IB) in W1, W2, and W3 were decreased significantly because more water was supplied. Under the experimental condition, the W1 regime was considered as the optimum. In this regime, the relative soil moisture contents in the 0–140 cm soil layer were controlled to 80% at sowing, 70% at jointing, and 70% at anthesis stages. When 43.8 and 13.8 mm of water was supplied in the 2007–2008 and 2008–2009 growing seasons, the final grain yields of W1 treatment were 8837.8 kg ha −1 and 9040.9 kg ha −1 , respectively, and the WUE I and WUE P were the highest among the 4 treatments.

Effects of Tillage Practices on Water Consumption, Water Use Efficiency and Grain Yield in Wheat Field

Abstract Water shortage is a serious issue threatening the sustainable development of agriculture in the North China Plain, with the winter wheat ( Triticum aestivum L.) as its largest water-consuming crop. The effects of tillage practices on the water consumption and water use efficiency (WUE) of wheat under high-yield conditions using supplemental irrigation based on testing soil moisture dynamic change were examined in this study. This experiment was conducted from 2007 to 2010, with five tillage practice treatments, namely, strip rotary tillage (SR), strip rotary tillage after subsoiling (SRS), rotary tillage (R), rotary tillage after subsoiling (RS), and plowing tillage (P). The results showed that in the SRS and RS treatments the total water and soil water consumptions were 11.81, 25.18% and 12.16, 14.75% higher than those in SR and R treatments, respectively. The lowest ratio of irrigation consumption to total water consumption in the SRS treatment was 18.53 and 21.88% for the 2008–2009 and 2009–2010 growing seasons, respectively. However, the highest percentage of water consumption was found in the SRS treatment from anthesis to maturity. No significant difference was found between the WUE of the flag leaf at the later filling stage in the SRS and RS treatments, but the flag leaf WUE at these stages were higher than those of other treatments. The SRS and RS treatments exhibited the highest grain yield (9573.76 and 9507.49 kg ha −1 for 3-yr average) with no significant difference between the two treatments, followed by P, R and SR treatments. But the SRS treatment had the highest WUE. Thus, the 1-yr subsoiling tillage, plus 2 yr of strip rotary planting operation may be an efficient measure to increase wheat yield and WUE.

Effects of Soil Tillage Practice on Dry Matter Production and Water Use Efficiency in Wheat

Abstract The objective of this study was to understand the effects of tillage practice on water consumption characteristics and dry matter accumulation and distribution in wheat (Triticum aestivum L.) plant under high-yielding and flexible irrigation conditions. In a fixed position experiment across 3 growing seasons from October 2007 to June 2010, only one wheat cultivar, Jimai 22, was planted in the field. In the 2007–2008 wheat season, 5 tillage treatments were designed, which were strip rotary tillage (SR), strip rotary tillage after subsoiling (SRS), rotary tillage (R), rotary tillage after subsoiling (RS), and plowing tillage (P). The same treatments were arranged in the same field plots in the 2008–2009 and 2009–2010 wheat seasons, except that SRS and RS had no subsoiling. All tillage treatments were irrigated at sowing, jointing, and anthesis stages to designed soil water content based on testing soil moisture before watering. The total water consumption was higher in SRS and RS treatments than in SR and R treatments. Treatment SRS increased the amount of soil water consumption in 0–200 cm soil layers but decreased the soil evaporation, compared to other treatments. Treatments SRS and RS gained the highest amount of dry matter accumulation, grain dry matter partitioning at maturity, and contribution to grain of dry matter assimilation after anthesis, followed by treatment P, and treatments R and SR showed the lowest levels in the above parameters, particularly SR. In the experiment across 3 years, SRS obtained the grain yields of 9409.01 kg ha−1 in 2008, 9613.86 kg ha−1 in 2009, and 9698.42 kg ha−1 in 2010, which were equivalent to that of RS but significantly higher than other treatments. Treatments P and R also exhibited higher yield level than SR treatment. In the 2008–2009 and 2009–2010 growing years, the water use efficiencies of SRS treatment were the highest among treatments, which were 21.39 kg ha−1 mm−1 and 22.09 kg ha−1 mm−1, respectively. Treatment RS also had higher water use efficiency than SR, R, and P treatments. Therefore, SRS is recommended as the optimal tillage practice in high-yielding and water-saving production system in the Yellow-Huai-Hai River Valleys Plain.

Effects of Nitrogen Application Depth on Water Consumption Characteristics and Dry Matter Accumulation and Distribution in Rainfed Wheat

To raise a suitable nitrogen application depth for rain-fed wheat in the Yellow-Huai Rivers Zone in China,we tested the water consumption characteristics and dry matter accumulation amounts and distribution ratios of wheat cultivars Shannong 16 and Yannong 0428 under different nitrogen application depths in 2010-2011 and 2011-2012 growing seasons.The nitrogen application depths were designed in four levels,which were surface application(D1) and application depths of 10 cm(D2),20 cm(D3),and 30 cm(D4).Compared to D1 and D2,D3 and D4 exhibited significantly greater water consumption amounts in the periods of jointing-anthesis and anthesis-maturity and soil water consumption amounts in 40-120 cm soil layers(P 0.05).In the 2011-2012 growing season with sufficient precipitation,the 120-160 cm soil water consumption amounts of D3 and D4 treatments were 4.0-5.3 mm greater than those of D1 and D2(P 0.05).These results indicated that nitrogen applied in 20-30 cm of soil depth could increase the utilization of soil water,particularly deep soil water,to meet the water requirement of wheat plant after jointing stage.Besides,D3 and D4 treatments also showed dramatically higher dry matter accumulation amounts from jointing to maturity than D1 and D2 treatments(P 0.05).After anthesis,the dry matter accumulation amounts in D3 and D4 were 394.5-723.1 kg ha 1 higher than those in D1 and D2,and at maturity stage,the increments were 642.1-2006.8 kg ha 1.The grain yields and partial factor productivities of nitrogen in D3 and D4 were significantly higher than those in D3 and D4,and no significant difference between D3 and D4.Besides,D3 had relatively higher water use efficiency.Therefore,we suggest that 20 cm is the optimal soil depth of nitrogen fertilizer application for rain-fed wheat in Huang-Huai Rivers Zone.

Characteristics of Water Use and Dry Matter Accumulation and Distribution in Different High-yielding Wheat Cultivars under Supplemental Irrigation Based on Soil Moisture

Water shortage is a serious problem threatening sustainable agricultural development in the North China Plain, where winter wheat(Triticum aestivum L.) is the largest water-consuming crop. The objective of this study was to guide wheat production in this area by selecting high water efficient cultivar and improving irrigation regime. In a two-year field experiment from autumn of 2007 to summer of 2009, irrigation quantum was controlled based on testing soil moisture(SM) in 0–140 cm depth,which was designed in low(SM of 65% at jointing and 55%–60% at anthesis stage), medium(SM of 75% at jointing and65%–70% at anthesis stage), and high(SM of 75% at jointing and 75% at anthesis stage) levels. Water use efficiency(WUE), dry matter accumulation and distribution in wheat plant, and grain yield were tested and compared among 14 commercial cultivars.Based on grain yield and WUE, the 14 cultivars were clustered into three groups, namely, super-high yield and high WUE group(I), super-high yield and medium WUE group(II), and high yield and low WUE group(III). One representative cultivar was selected from each group to compare the amount and proportion of water consumption during sowing–jointing, jointing–anthesis,and anthesis–maturity periods. Shannong 15 from group I had significantly lower water consumption from sowing to jointing than Jimai 22 from group II and Yannong 21 from group III, and significantly higher water consumption from jointing to anthesis.However, water consumption amount and proportion had no significant differences among the three cultivars from anthesis to maturity. Under medium SM condition, soil water consumption in Shannong 15 was significantly higher than that in Jimai 22 and Yannong 21, but such advantage in Shannong 15 disappeared under high SM condition. Under medium and high SM conditions,translocation amount and ratio of dry matter accumulated before anthesis and its contribution to grain were significantly higher in Shannong 15 than in Jimai 22 and Yannong 21. Among the three cultivars, harvest index was the highest in Shannong 15, the medium in Jimai 22, and the lowest in Yannong 21.