Juvenile Heat Tolerance in Wheat for Attaining Higher Grain Yield by Shifting to Early Sowing in October in South Asia

Farmers in northwestern and central India have been exploring to sow their wheat much earlier (October) than normal (November) to sustain productivity by escaping terminal heat stress and to utilize the available soil moisture after the harvesting of rice crop. However, current popular varieties are poorly adapted to early sowing due to the exposure of juvenile plants to the warmer temperatures in the month of October and early November. Therefore, a study was undertaken to identify wheat genotypes suited to October sowing under warmer temperatures in India. A diverse collection of 3322 bread wheat varieties and elite lines was prepared in CIMMYT, Mexico, and planted in the 3rd week of October during the crop season 2012–2013 in six locations (Ludhiana, Karnal, New Delhi, Indore, Pune and Dharwad) spread over northwestern plains zone (NWPZ) and central and Peninsular zone (CZ and PZ; designated as CPZ) of India. Agronomic traits data from the seedling stage to maturity were recorded. Results indicated substantial diversity for yield and yield-associated traits, with some lines showing indications of higher yields under October sowing. Based on agronomic performance and disease resistance, the top 48 lines (and two local checks) were identified and planted in the next crop season (2013–2014) in a replicated trial in all six locations under October sowing (third week). High yielding lines that could tolerate higher temperature in October sowing were identified for both zones; however, performance for grain yield was more promising in the NWPZ. Hence, a new trial of 30 lines was planted only in NWPZ under October sowing. Lines showing significantly superior yield over the best check and the most popular cultivars in the zone were identified. The study suggested that agronomically superior wheat varieties with early heat tolerance can be obtained that can provide yield up to 8 t/ha by planting in the third to fourth week of October.

Impact of Soil Moisture on Crop Yields in Major Rainfed Growing Regions of Peninsular India

Assessment of soil moisture availability and timely declaration of drought are keys for exemplary relief assistance in water stressed regions. Percent available soil moisture (PASM) is one among several drought declaration indices, needs evaluation with respect to individual crop and cropping system, as the amount of water requirement varies with respect to crop and its growth stage. Analysis of yield variability due to PASM was carried out by employing correlation and linear regression analyses based on long term observations in experiments conducted at different dry farming locations of the peninsular India. The range of available soil moisture in order to obtain at least 50 per cent of optimum yield in cereals (maize: 26 and finger millet: 52.9 PASM), pulses (pigeonpea: 37.2 PASM), oilseeds (soybean: 26.8 to 30.5, groundnut: 53.8 to 61.7 PASM) and commercial crops (cotton: 26.3 PASM) was 26 to 61 per cent. Establishment of these regression models helped in timely drought declaration / precise identification of drought hit areas and assuring feasible relief assistance. The outcomes of the study may be used for amending the existing drought norms (0–50; severe, 50–75; mild and 75–100; no drought) for provision of proportionate compensations to the farmers.

A roadmap for high-resolution satellite soil moisture applications

<p>This contribution presents the main findings of a recently published review on high-resolution satellite soil moisture applications (https://doi.org/10.1016/j.rse.2020.112162). The scientific community has made significant progress in estimating soil moisture from satellite-based Earth observation data, particularly in operationalizing coarse-resolution (25-50 km) soil moisture products. This presentation summarizes existing applications of satellite-derived soil moisture products and identifies gaps between the characteristics of currently available soil moisture products and the application requirements from various disciplines. This presentation also discusses the efforts devoted to the generation of high-resolution soil moisture products from satellite Synthetic Aperture Radar (SAR) data such as Sentinel-1 C-band backscatter observations and through downscaling of existing coarse-resolution microwave soil moisture products. Open issues and future opportunities of soil moisture remote sensing are discussed, providing guidance for the further development of operational soil moisture products and for bridging the gap between the soil moisture user and supplier communities.</p><p>The <span>published review </span>is:</p><p>Peng, J., Albergel, C., Balenzano, A., Brocca, L., Cartus, O., Cosh, M.H., Crow, W.T., Dabrowska-Zielinska, K., Dadson, S., Davidson, M.W.J., de Rosnay, P., Dorigo, W., Gruber, A., Hagemann, S., Hirschi, M., Kerr, Y.H., Lovergine, F., Mahecha, M.D., Marzahn, P., Mattia, F., Musial, J.P., Preuschmann, S., Reichle, R.H., Satalino, G., Silgram, M., van Bodegom, P.M., Verhoest, N.E.C., Wagner, W., Walker, J.P., Wegmüller, U., & Loew, A. (2021). A roadmap for high-resolution satellite soil moisture applications – confronting product characteristics with user requirements. <em>Remote Sensing of Environment</em>, 252, 112162</p>

Throughfall and stemflow nutrient flux in deodar and oak forests, Garhwal Himalaya, India

A study to understand the throughfall and stemflow chemistry under deodar and oak forests of Garhwal Himalaya was conducted during 2014–2015. Total rainfall during experimental period was 1473.8 mm and estimated interception loss was 34.018% for deodar forest, 24.85% for oak forest. Stemflow represented the minimum proportion of gross rainfall, i.e. 0.321% in deodar forest and 0.463% in oak forest. pH of throughfall and stemflow in both deodar (6.087 and 6.47 respectively) and oak forests (6.75 and 7.03 respectively) was significantly more acidic than the gross rainfall (7.15). Electrical conductivity was recorded higher in deodar stemflow (231.89 μs/cm) and throughfall (102.75 μs/cm) compared to oak forest (172.92 μs/cm and 83.83 μs/cm respectively). Net nutrient leaching and stemflow were considerably higher from oak forest than deodar forest. Oak forest has better water yield capacity than deodar forest as the interception loss was higher in deodar forest. The idea of sustainable agriculture may be possible surrounding such forests as the need for chemical fertilizer and water can be met by the nutrient-rich soil, available soil moisture and surface water.

SOIL MOISTURE AVAILABILITY IN AN ORCHARD AND THE NEED FOR ITSREGULATION

The growth and fruiting of fruit crops is interconnected with the biotic and abiotic conditions of the natural envi-ronment as water, heat and nutritional regimes in the soil which continuously change in space and time. The main limiting factor in the forest-steppe zone of the Altai Region is the moisture content in the soil profile since plants often suffer from moisture deficit. The available soil moisture (ASM) storage in the apple orchard in April 2012 was satis-factory. In Mayand in the summer, they dropped to zero, so the plants suffered from water hunger during the grow-ing season. Under pears, at the beginning of the growing season, the ASM turned out to be higher than under the apple trees, but from June to August they alsodecreased. As a result, the irrigation rates were the same as for the apple trees. The summer of 2013 was rainy and that af-fected the water resources in the chernozem layer. At the same time, the ASM deficit did not exceed 85 mm in June and July, and in the remaining periods did not rise above 50 mm. In the pear orchard, the moisture storage did not fall below 30 mm. In one-meter chernozem layer in April 2012, the available soil moisture storage under the apple trees corresponded to a very good level. In June and July, the moisture content dropped below the wilting moisture. In spring, the ASM under the pear plantations were consid-ered satisfactory. On the following months, a severe mois-ture deficit arose until autumn. In 2013, the ASM in the apple orchard did not exceed 50 mm in summer. Under the pears, in May they even reached 118 mm, but then dropped to 30 mm and that also required irrigation. Since the season of 2014 was an arid one, the water situation in one-meter layer of chernozem turned out to be disastrous.

Productivity of winter barley depending on preceding crops in Transcarpathia of Ukraine

Winter barley is a valuable food, fodder, and technical crop. Our research is aimed at obtaining economically and energy-efficient, adequate to the bioresource potential of winter barley grain yield, depending on the preceding crops in Transcarpathia of Ukraine. Research and balance calculations available soil moisture showed that the conditions of Transcarpathia it is negative and ranges from 250 to 1210 tons / ha or 25-121 mm. Accumulation and efficient use of available moisture in the soil depends on the amount of precipitation and their frequency of precipitation, crop rotation (preceding crops), tillage system, fertilization, and weediness of fields. The largest reserves of available moisture in the soil during the sowing of winter barley were after winter rape and buckwheat, the smallest – after sunflower and, especially, corn for grain. During the autumn-winter period, the reserves of available moisture in a meter layer of soil were replenished by 21-35%, but the influence of preceding crops remained. The critical period of winter barley in terms of moisture occurs during earing - grain filling. Preceding crops of early harvesting (winter oilseed rape and buckwheat) have a positive effect on the accumulation and retention of moisture in the soil. Late harvest preceding crops (maize for grain and sunflower) reduce the available moisture content and reserves by up to 18% compared to early harvest crops. On average over three years, the highest yield of winter barley was after buckwheat and amounted to 5.9 t / ha, the lowest - after corn for grain and was at 4.9 t / ha, which is 0.8 t / ha lower than the control variant.

Irrigation management strategies for reducing verticillium wilt severity in eggplants

ABSTRACT Verticillium wilt in eggplants is a root disease of difficult control. In this study, we report the relationship between soil water availability and the disease intensity in order to identify management strategies that are unfavourable to the pathogen and capable of reducing the disease progression and the damage caused by it. Four irrigation management strategies were compared in soil infested or not infested with Verticillium dahliae, which consisted of: irrigating when the available soil moisture was maintained at 90% (WA90%), 55% (WA55%) and 20% (WA20%) during the entire growing cycle, and kept at 20% in the vegetative stage, and at 90% in the production stage (WA20-90%). Experimental design was in randomized blocks, including eight treatments in factorial arrangement (4x2) and three replicates. The management strategy WA20-90% led to a significant reduction in the disease severity and in the extent of xylem colonization by the pathogen. The dry mass of plants in infested soil was 12% lower than that of control treatments and was higher with the irrigation strategy WA90% than with WA55% or WA20%. The strategy WA20-90% was efficient in reducing the disease with no significant reduction in dry mass.