Showing papers on "Sowing published in 2019"

Seed priming in field crops: potential benefits, adoption and challenges

Abstract: Seed priming is a presowing technique in which seeds are moderately hydrated to the point where pregermination metabolic processes begin without actual germination. Seeds are then redried to near their actual weight for normal handling. Seeds can be soaked in tap water (hydropriming), aerated low-water potential solutions of polyethylene glycol or salt solutions (KNO3, KH2PO4, KCl, NaCl, CaCl2 or MgSO4; osmopriming), plant growth regulators, polyamines (hormonal priming), plant growth-promoting bacteria (biopriming), macro or micronutrients (nutripriming) or some plant-based natural extracts. Here, we review: (1) seed priming as a simple and effective approach for improving stand establishment, economic yields and tolerance to biotic and abiotic stresses in various crops by inducing a series of biochemical, physiological, molecular and subcellular changes in plants; (2) the tendency for seed priming to reduce the longevity of high-vigour seeds and improve the longevity of low-vigour seeds; (3) the advantages of physical methods of seed priming to enhance plant production over conventional methods based on the application of different chemical substances; (4) the various physical methods (e.g. magneto-priming and ionising radiation, including gamma rays, ultraviolet (UV) rays (UVA, UVC) and X-rays) available that are the most promising presowing seed treatments to improve crop productivity under stressful conditions; and (5) effective seed priming techniques for micronutrient delivery at planting in field crops. Seed priming as a cost-effective approach is being used for different crops and in different countries to improve yield, as a complementary strategy to grain biofortification and in genetically improved crop varieties to enhance their performance under stress conditions, including submergence and low phosphorus. Some of the challenges to the broad commercial adaption of seed priming include longevity of seeds after conventional types of priming under ambient storage conditions and a lack of studies on hermetic packaging materials for extended storage.

Assessing Variation in US Soybean Seed Composition (Protein and Oil)

Abstract: Soybean [Glycine max (L.) Merr.] seed composition and yield are a function of genetics (G), environment (E), and management (M) practices, but contribution of each factor to seed composition and yield are not well understood. The goal of this synthesis-analysis was to identify the main effects of G, E, and M factors on seed composition (protein and oil concentration) and yield. The entire dataset (13,574 data points) consisted of 21 studies conducted across the United States (US) between 2002 and 2017 with varying treatments and all reporting seed yield and composition. Environment (E), defined as site-year, was the dominant factor accounting for more than 70% of the variation for both seed composition and yield. Of the crop management factors: (i) delayed planting date decreased oil concentration by 0.007 to 0.06% per delayed week (R 2∼0.70) and a 0.01 to 0.04 Mg ha-1 decline in seed yield per week, mainly in northern latitudes (40-45 N); (ii) crop rotation (corn-soybean) resulted in an overall positive impact for both seed composition and yield (1.60 Mg ha-1 positive yield difference relative to continuous soybean); and (iii) other management practices such as no-till, seed treatment, foliar nutrient application, and fungicide showed mixed results. Fertilizer N application in lower quantities (10-50 kg N ha-1) increased both oil and protein concentration, but seed yield was improved with rates above 100 kg N ha-1. At southern latitudes (30-35 N), trends of reduction in oil and increases in protein concentrations with later maturity groups (MG, from 3 to 7) was found. Continuing coordinated research is critical to advance our understanding of G × E × M interactions.

Planting Date, Hybrid Maturity, and Weather Effects on Maize Yield and Crop Stage

Abstract: 303 Planting date and hybrid maturity are two major strategies used worldwide for crop adaptation and mitigation to manage for unfavorable growing conditions. Planting date (PD) and hybrid relative maturity (RM) decisions set the yield potential of maize in each environment. Together with the prevailing weather, these two factors control the length of the growing season in which the crop accumulates radiation that is positively correlated with grain yield (Lindquist et al., 2005). For field crops it is accepted that early planting with a full-season RM has greater yield potential than a late planting with a short-season RM (Richards, 1996), because the larger length of the growing season allows for greater use of resources such as radiation, water, and nutrients by the crop (Andrade et al., 2000; Tsimba et al., 2013a; Parker et al., 2016). However, yield is particularly sensitive to growth and partitioning during critical periods (Andrade et al., 2000; Vega et al., 2001), an early PD and full-season hybrid does not guarantee a high grain yield because other factors such as drought, heat, and nutrient stresses can reduce grain yield during the season (Edmeades et al., 2000). According to the literature, the optimum planting window for maize in the US Corn Belt was determined to be the last week of April (Nafziger, 1994). Within each state, there are different optimum planting window recommendations, depending on location (Sindelar et al., 2010; Abendroth et al., 2017). When maize is planted prior to or later than this optimum window, a yield decline can be observed (Zhou et al., 2016). The optimum timeframe for maize establishment usually refers to the mean weather conditions and does not apply every year. The reality is that year-to-year weather variability and poor soil conditions in the spring forces farmers to frequently plant outside the optimum window. Very early planting increases the probability of poor planting conditions due to cold, wet soils, resulting in a negative impact on plant emergence (Parker et al., 2016). For that reason, replanting maize is a practice that increases the operation cost (Benson, 1990). On the other hand, very late planting is associated with reduction in growing season length and accumulation of radiation (Nielsen et al., 2002). In the US Corn Belt, farmers typically select the hybrids to use several months before the planting season. They make decisions based on university extension or seed company recommendations for average weather years that are usually limited Planting Date, Hybrid Maturity, and Weather Effects on Maize Yield and Crop Stage

Effect of planting patterns on yield, nutrient accumulation and distribution in maize and soybean under relay intercropping systems

Abstract: Planting patterns affect nitrogen (N), phosphorus (P), and potassium (K) acquisition and distribution in maize and soybean under intercropping conditions. Here we reveal that strip relay-intercropping increases the N, P, and K uptake and distribution across plant organs (root, straw, and seed) of maize and soybean, accelerates the dry-matter production of intercrop-species, and compensates the slight maize yield loss by considerably increasing the soybean yield. In a two-year experiment, soybean was planted with maize in different planting patterns (SI, 50:50 cm and SII, 40:160 cm) of relay-intercropping, both planting patterns were compared with sole cropping of maize (SM) and soybean (SS). As compared to SI, SII increased the N, P, and K accumulation in each organ of soybean by 20, 32, and 18 (root) %, 71, 61, and 76 (straw) %, and 68, 65, and 62 (seed) %, respectively, whereas decreased the N, P, and K accumulation in each organ of maize by 1, 4, and 8 (root) %, 1, 10, and 3 (straw) %, and 5, 10, and 8 (seed) %, respectively. Overall, in SII, relay-cropped soybean accumulated 91% of total nutrient uptake (TNU) of sole soybean plants, and relay-cropped maize accumulated 94% of TNU of sole maize plants.

Effects of tillage practices on water consumption and grain yield of dryland winter wheat under different precipitation distribution in the loess plateau of China

Abstract: Deep ploughing and subsoiling are important management practices used for mitigating the risk of soil compaction under long term no-tillage or reduced tillage practices. These fallow tillage methods have been widely applied in the Loess Plateau region of China to improve soil water availability and preventing soil erosion. To investigate the effect of different tillage practices for increasing the production of winter wheat (Triticum aestivum L.) and their relationship with precipitation distribution in the semiarid southeast region of the Loess Plateau, a six-year field study was conducted from 2009 to 2015, using three tillage treatments: deep ploughing (DP), subsoiling (SS), and no-tillage (NT). Our results indicated that DP and SS treatments increased soil water storage in the 0–300 cm soil layer at sowing and soil organic carbon in the 0–20 cm soil layer at maturity. In addition, DP and SS increased soil water consumption in the 0–180 cm soil layer from sowing to anthesis, and in the 120–300 cm layer from anthesis to maturity of wheat. Furthermore, the DP and SS treatments significantly increased the root length, root surface area, and the number of root tips in the 0–80 cm and aboveground dry biomass at maturity. Additionally, DP and SS treatments increased the grain yield by 31% and 26%, precipitation use efficiency by 32% and 26%, and water use efficiency by 12% and 11% respectively, as compared with those of the NT treatments. Pearson’s correlation analysis showed that soil water consumption was significantly positively correlated with precipitation from sowing to jointing and anthesis to maturity. In addition, grain yield had a significant positive correlation with precipitation during the fallow season, particularly in the SS treatment. Moreover, grain yield was significantly positively correlated with soil water consumption in the 0–180 cm soil layer from sowing to jointing, and at 60–240 cm soil depth from jointing to maturity. In conclusion, under low precipitation, DP was more favorable for winter wheat than SS, whereas, under high precipitation, SS was more beneficial than DP.

Narrow-wide row planting pattern improves the light environment and seed yields of intercrop species in relay intercropping system

Abstract: Different planting patterns affect the light interception of intercrops under intercropping conditions. Here we revealed that narrow-wide-row relay-intercropping improves the light interception across maize leaves in wide rows (60cm) and narrow rows (40cm), accelerated the biomass production of intercrop-species and compensated the slight maize yield loss by considerably increasing the soybean yield. In a two-year experiment, maize was planted with soybean in different planting patterns (1M1S, 50:50cm and 2M2S, 40:60cm) of relay-intercropping, both planting patterns were compared with sole cropping of maize (M) and soybean (S). As compared to M and 1M1S, 2M2S increased the total light interception of maize leaves in wide rows (WR) by 27% and 23%, 20% and 10%, 16% and 9% which in turn significantly enhanced the photosynthetic rate of WR maize leaves by 7% and 5%, 12% and 9%, and 19% and 4%, at tasseling, grain-filling and maturity stage of maize, respectively. Similarly, the light transmittance at soybean canopy increased by 218%, 160% and 172% at V2, V5 and R1 stage in 2M2S compared with 1M1S. The improved light environment at soybean canopy in 2M2S considerably enhanced the mean biomass accumulation, and allocation to stem and leaves of soybean by 168%, and 131% and 207%, respectively, while it decreased the mean biomass accumulation, and distribution to stem, leaves and seed of maize by 4%, and 4%, 6% and 5%, respectively than 1M1S. Compared to 1M1S, 2M2S also increased the CR values of soybean (by 157%) but decreased the CR values of maize (by 61%). Overall, under 2M2S, relay-cropped maize and soybean produced 94% and 69% of the sole cropping yield, and the 2M2S achieved LER of 1.7 with net income of 1387.7 US $ ha-1 in 2016 and 1434.4 US $ ha-1 in 2017. Our findings implied that selection of optimum planting pattern (2M2S) may increase the light interception and influence the light distribution between maize and soybean rows under relay-intercropping conditions which will significantly increase the intercrops productivity. Therefore, more attention should be paid to the light environment when considering the sustainability of maize-soybean relay-intercropping via appropriate planting pattern selection.

Hydro-priming effects on seed germination and field performance of faba bean in spring sowing.

Abstract: Seed priming has been used to advance germination and stand in several crops, but relevant research on faba bean (Vicia faba L.) is scarce. Laboratory and field trials were carried out for two years to study the effect of hydro-priming on faba bean germination and field performance in spring sowing. In laboratory trials, the effects of hydro-priming for 0, 8, 16, 24, 36, and 48 h on final germination percentage, germination speed, Timson’s germination index, mean germination time, mean daily germination, synchronization index, and seedling vigor index were studied. All hydro-priming treatments improved germination parameters of faba bean seeds, except for final germination percentage and mean daily germination compared with non-primed seeds. Averaged over priming duration treatments, hydro-priming improved germination speed by 16.2%, germination synchrony by 20.7%, and seedling vigor index by 13.4%. All hydro-priming durations improved germination synchrony, while hydro-priming for 8, 16, and 24 h provided the highest values of germination speed (2.56, 2.58, and 2.37 seeds day−1, respectively). Hydro-priming for 8 and 16 h provided the lowest values of mean germination time (5.81 and 5.96 days, respectively). In field trials, hydro-priming periods of 0, 8, 16, and 24 h were compared. On average, seed hydro-priming did not affect significantly seedling emergence 14 days after sowing in the first year, but significantly improved seedling emergence by 34.4% in the second year. No significant effect of seed hydro-priming was noted in the number of plants at 28 and 35 days after sowing. Seed priming for 8 h resulted in higher fresh weight at anthesis by 22.3% and 8.6% in the first and the second year, respectively, than the non-primed control. Similarly, seed priming for 8 h provided higher seed yield by 12.0% in the first year and by 5.9% in the second year compared with non-primed control. Overall, seed hydro-priming accelerated faba bean germination and seedling emergence, but the magnitude of the response was associated with the environment and was more evident under limited soil moisture after sowing, whereas the beneficial effect of priming was masked when rainfall followed sowing. Similarly, the beneficial effect of priming on seed yield was more pronounced with limited soil moisture after anthesis.

Narrow‐wide‐row planting pattern increases the radiation use efficiency and seed yield of intercrop species in relay‐intercropping system

Abstract: Planting arrangements affect radiation use efficiency (RUE) and competitiveness of intercrop species in intercropping systems. Here, we reveal that narrow-wide-row planting arrangement in maize-soybean relay-intercropping system increases the dry matter and competitiveness of soybean, increased the RUE of maize and soybean, and compensates the yield loss of maize by substantially increasing the yield of soybean. In this field study, maize was planted with soybean in different planting arrangements (P1, 20:180, P2, 40:160; P3, 60:140, and P4, 80:120) of relay intercropping, all the relay-intercropping treatments were compared with sole crops of maize (SM) and soybean (SS). Results showed that P1 improved the total RUE 3.26 g/MJ (maize RUE + soybean RUE) of maize and soybean in relay-intercropping system. Compared to P4, treatment P1 increased the soybean competition ratio (CR) values (by 55%) but reduced the maize CR values (by 29%), which in turn significantly improved the yield of soybean by maintaining the maize yield. Generally, in P1, soybean produced 82% of SS yield, and maize produced 88% of SM yield, and it achieved the land equivalent ratio of 1.7. These results suggest that by maintaining the appropriate planting distances between maize and soybean we can improve the competitiveness and yield of intercrop species in relay-intercropping system.

Rapid and Nondestructive Measurement of Rice Seed Vitality of Different Years Using Near-Infrared Hyperspectral Imaging.

Abstract: Seed vitality is one of the primary determinants of high yield that directly affects the performance of seedling emergence and plant growth. However, seed vitality may be lost during storage because of unfavorable conditions, such as high moisture content and temperatures. It is therefore vital for seed companies as well as farmers to test and determine seed vitality to avoid losses of any kind before sowing. In this study, near-infrared hyperspectral imaging (NIR-HSI) combined with multiple data preprocessing methods and classification models was applied to identify the vitality of rice seeds. A total of 2400 seeds of three different years: 2015, 2016 and 2017, were evaluated. The experimental results show that the NIR-HSI technique has great potential for identifying vitality and vigor of rice seeds. When detecting the seed vitality of the three different years, the extreme learning machine model with Savitzky-Golay preprocessing could achieve a high classification accuracy of 93.67% by spectral data from only eight wavebands (992, 1012, 1119, 1167, 1305, 1402, 1629 and 1649 nm), which could be developed for a fast and cost-effective seed-sorting system for industrial online application. When identifying non-viable seeds from viable seeds of different years, the least squares support vector machine model coupled with raw data and selected wavelengths of 968, 988, 1204, 1301, 1409, 1463, 1629, 1646 and 1659 nm achieved better classification performance (94.38% accuracy), and could be adopted as an optimal combination to identify non-viable seeds from viable seeds.

Mitigating heat and chilling stress by adjusting the sowing date of maize in the North China Plain

Abstract: The North China Plain (NCP) is one of the major areas of cereal production, and in recent years its maize (Zea mays L.) production has been influenced by both heat and chilling stresses. Adjusting the sowing date is an effective measure for mitigating these stresses. However, the underlying mechanisms remain poorly understood. We performed a 5‐year field experiment to determine how the sowing date mitigated heat and chilling stresses at Wuqiao Experimental Station in the NCP with three treatments: early sowing (ES), middle sowing (MS), and late sowing (LS). In all 5 years, higher grain yields were observed in the MS (averaged 11.7 Mg/ha) and LS (averaged 11.4Mg/ha) treatments compared with the ES (averaged 10.9Mg/ha) treatment. The lower yield in ES treatment mainly resulted from high temperature 5 days pre‐silking and 5 days post‐silking (>31.8°C). In 2015 and 2016, the lower grain yield in LS (11.4Mg/ha in 2015 and 11.2Mg/ha in 2016) treatment compared with MS (12.1Mg/ha in 2015 and 11.9Mg/ha in 2016) was mainly because the minimum temperature was <13.0°C 5 days before maturity or <13.6°C 10 days before maturity. Long‐term weather data further verified middle sowing would be appropriate in a changing climate. Therefore, we can conclude that sowing date manipulation constitutes a useful method for mitigating heat and chilling stresses for maize production.

Ascorbic Acid Priming Enhances Seed Germination and Seedling Growth of Winter Wheat under Low Temperature Due to Late Sowing in Pakistan

Abstract: Poor seed germination is a crucial yield-limiting factor when winter wheat is sown under low temperature. The objective of this study was to evaluate the role of ascorbic acid (AsA) in the extenuation of the harmful effects of low temperature at early and reproductive stages of wheat during 2016–2017 (15 November to 15 December). A two-year experiment was conducted using a randomized complete block design with split plot arrangement and with three replicates. Sowing dates (15 November and 15 December) were allotted to the main plot while seed priming (control, hydro-priming, and AsA priming) were allotted to the sub-plot. Results demonstrated that AsA priming significantly boosted different yield characteristics including chlorophyll content, tillers per unit area, number of grains per spike, and 1000-grain weight, contributing higher productivity and biomass during 2016–2017. The results further revealed that AsA could induce the up-regulation of diverse antioxidants (super oxide dismutase (SOD), peroxidase (POD), and catalase (CAT)), thus offsetting the adverse effects of sub-supra optimum temperatures of late sowing wheat. It is therefore concluded in this work that AsA priming enhances stand establishment, yield and yield-related traits, antioxidant enzyme activities, and chlorophyll contents when wheat is sown under low temperature.

Effects of film mulching and nitrogen fertilization on rhizosphere soil environment, root growth and nutrient uptake of winter oilseed rape in northwest China

Abstract: The ridge film mulching and furrow planting (RFMF) pattern has been increasingly applied to the production of wheat, maize, and potato in arid and semiarid regions of northwest China because it can significantly improve crop yield. How RFMF affects the productivity and whether it can improve the rhizosphere soil environment of winter oilseed rape (Brassica napus L.) is not clear. The main objective of the present study was to determine whether RFMF can improve rhizosphere soil environment and winter oilseed rape productivity in comparison to the conventional flat planting (FP) pattern in a three-year (2014-2017) field experiment. In combination with each planting pattern, we determined an optimal nitrogen (N) application rate among six levels: 0 (N0), 60 (N60), 120 (N120), 180 (N180), 240 (N240) and 300 (N300) kg N ha−1. Results showed that the RFMF pattern significantly improved the rhizosphere soil environment by increasing soil moisture by 0.3–5.6% and soil temperature by 0.6–3.0 °C. However, soil oxygen concentration decreased by 0.03–5.66% during the flowering stage of winter oilseed rape. In addition, the RFMF pattern markedly improved rhizosphere soil enzyme activity and microorganism abundance and thus promoted root growth, nutrient uptake, and seed yield of winter oilseed rape. The resulting optimal N application rates remarkably improved rhizosphere soil enzyme activity, microorganism abundance, root growth, nutrient uptake, and yield of winter oilseed rape in both RFMF and FP treatments. In the RFMF treatment, N240 obtained significantly greater rhizosphere soil enzyme activity, microorganism abundance, root growth parameters, nutrient uptake, and seed yield than N0, N60, N120, and N180, with no significant differences observed between N240 and N300. In conclusion, the RFMF pattern in combination with the optimal N-application rate of 240 kg ha−1 has great potential to improve rhizosphere environment and winter oilseed rape productivity in arid and semiarid regions of northwest China.

Bacterial Consortium for Improved Maize (Zea mays L.) Production.

Abstract: The ever-increasing human population is a major concern for food security. Maize is the third largest most important food crop. The major problems of cultivation arise from urbanization and land pollution. This reduces the amount of land available for agriculture. The use of chemicals in agriculture is not environmentally friendly. Thus, plant growth-promoting bacteria (PGPB) have been proposed as alternatives. This study aims to test the growth-promoting effect of maize inoculated with six indigenous PGPB isolates. These isolates were assayed for various biochemical and plant growth-promoting activities. They were also assayed for biocontrol activities. Based on the results, six isolates viz A1, A18, A29, NWU4, NWU14, and NWU198 were used to inoculate maize seeds. The inoculated seeds were tried out on the field. A randomized block design was used. PGPB used were in single, consortia of two, and three organisms. The length of the leaves, roots, and stem, plant height, numbers of leaves, and weight of 100 seeds were taken at the fourth and eighth weeks after planting. Microbial consortia increased growth parameters compared to single inoculant treatments. Thus, they can be of advantage in the eradication of low yield. They can also serve as reliable alternatives to chemical fertilizers.

Glyphosate residues in soil affect crop plant germination and growth

Abstract: Glyphosate-based herbicides (GBH) are the most widely used pesticides globally. Their persistence in soils and effects on non-target organisms have become a concern in agricultural and natural ecosystems. We experimentally studied, whether residues of GBH (Roundup Gold) or pure glyphosate in soils affect the germination or sprouting and growth of crop plants after the safety period. The seed germination of faba bean, oat and turnip rape, and sprouting of potato tubers was delayed in the greenhouse experiments in soils treated with GBH or with pure glyphosate. The total shoot biomass of faba bean was 28%, oat 29% and turnip rape 58% higher in control compared to GBH soils four weeks after sowing. In the beginning of the growing season, the plant growth in the field experiment supported the observations in the greenhouse experiment. However, at the end of the field experiment, potato shoot biomass was 25% and tuber biomass 14% greater in GBH soil compared to control soil. Potato tubers tended to gather low amounts of glyphosate (0.02 mg/kg) and its metabolite AMPA (0.07 mg/kg). Grazing by barnacle geese was three times higher in oats growing in the GBH soils compared to control oats in the field. Our results draw attention to complex indirect effects of GBH on crop plant seedling establishment and resistance to herbivores.

Economics and agronomics of relay-cropping pennycress and Camelina with Soybean in Minnesota

Abstract: Cover crops can serve as a valuable management tool for improving soil and water quality, but are an added expense for farmers. We evaluated the yields and economics of four cover crops and two winter fallow treatments in a spring wheat (Triticum aestivum L.)–soybean [Glycine max (L.) Merr.] rotation at three sites in Minnesota. The four cover crop treatments were winter rye (Secale cereal L.), forage radish (Raphanus sativus L.), winter camelina [Camelina sativa (L.) Crantz], and pennycress (Thlaspi arvense L.) planted into spring wheat stubble. The fallow treatments consisted of no-tilled and conventionally tilled soil. Radish winterkilled and rye was terminated chemically before planting soybean in early May. Soybean was inter-seeded between rows of camelina and pennycress at the same time it was planted in other treatments. Camelina and pennycress were harvested over soybean seedlings in late June. Camelina yields ranged from 600 to 1100 kg ha–¹, while pennycress ranged from 900 to 1550 kg ha–¹. Mono-cropped soybean averaged 1819, 3510, and 4180 kg ha–¹ in northern, central, and southern Minnesota, respectively. Soybean seedlings under oilseed cover crop canopies exhibited light-stress, which likely reduced soybean yield in these treatments by 22 to 30%. When oilseed and inter-seeded soybean yields were combined, total seed yields generally were equal to or exceeded those of mono-cropped soybean. In addition, net income for inter-seeded systems was typically equivalent to mono-cropped soybean. Improvements in net income are likely needed before the benefits of oilseed cover crops are fully realized.

Reduced Potential for Nitrogen Loss in Cover Crop-Soybean Relay Systems in a Cold Climate.

Abstract: Winter cover crops might reduce nutrient loss to leaching in the Upper Midwest. New oilseed-bearing cash cover crops, such as winter camelina ( L.) and pennycress ( L.), may provide needed incentives. However, the abilities of these crops to sequester labile soil nutrients are unknown. To address this unknown, N in shoot biomass, plant-available N and P in soil, and NO-N and soluble reactive P in soil water collected from lysimeters placed at 30, 60, and 100 cm were measured in cover crop and fallow treatments established in spring wheat ( L.) stubble and followed through a cover crop-soybean [ (L.) Merr.] rotation. Five no-till cover treatments (forage radish [ L.], winter rye [ L.], field pennycress, and winter camelina) were compared with two fallow treatments (chisel till and no-till). Pennycress and winter camelina were harvested at maturity after relay sowing of soybean. Winter rye and radish sequestered more N in autumn shoot biomass, ranging from 26 to 38 kg N ha, but overwintering oilseeds matched or exceeded N uptake in spring, ranging 28 to 49 kg N ha before soybean planting. Nitrogen uptake was reflected by reductions in soil water NO-N during cover crop and intercropping phases for all cover treatments (mean = 4 mg L), compared with fallow treatments (mean = 31 mg L). Cash cover crops like pennycress and winter camelina provide both environmental and potential economic resources to growers. They are cash-generating crops able to sequester labile soil nutrients, which protects and promotes soil health from autumn through early summer.

High intrinsic seed Zn concentration improves abiotic stress tolerance in wheat

Abstract: Abiotic stresses are threatening wheat productivity across the globe, which is often associated with nutrient deficiencies. Zinc (Zn) is involved in many physiological processes of plants, and high intrinsic seed Zn concentrations may help to improve the resistance of wheat to abiotic stresses. Three separate experiments evaluated the effect of intrinsic seed zinc on bread wheat resistance to abiotic stresses, viz. waterlogging, drought and salinity. One-week-old wheat seedlings raised from seeds containing either 49 mg (high), 42 mg (medium), or 35 mg (low) Zn kg−1 grain were exposed to waterlogging or drought stress for one week or until harvest. Salinity stress was applied at sowing for one week or until harvest. Plants with high intrinsic seed Zn performed better than those with medium or low Zn concentrations under each stress, including lower malondialdehyde contents and total antioxidant activities and more proline. The grain yield in plants from high, medium and low seed Zn concentrations increased by 10.5–48%, 12.2–21.5% and 7.7–21% under waterlogging, drought and salinity stress, respectively. Plants with high intrinsic seed Zn concentrations produced higher wheat grain yields than those with lower levels under abiotic stress by reducing oxidative damage and improving the growth and uptake of nutrients.

Sub-soiling improves productivity and economic returns of cotton-wheat cropping system

Abstract: Soil compaction in Indian Punjab is an emerging problem affecting crop productivity. Heavy machinery operations or repetitive tillage in fields are main reasons behind this problem. To investigate the direct and residual effect of sub-soiling on soil physical properties and productivity of cotton-wheat cropping system, we conducted a field experiment for three cropping cycles (2014-2017) at two different sites and evaluated a total of five treatments (Control, Sub-soiling at 1.0 m, Sub-soiling at 1.5 m, Cross Sub-soiling at 1.0 m and Cross Sub-soiling at 1.5 m) in complete randomized block design. Results elucidated that any level of sub-soiling if applied once, improved the infiltration rate besides reduction in the bulk density for two years. Consequently, higher root length and increased root mass of cotton under sub-soiled treatments revealed advantages by improvement in yield attributes and seed cotton. Cotton sown after sub-soiling recorded significantly higher seed cotton yield while control exhibited statistically least for two years. Sub-soiling applied prior to cotton sowing in initial year also had beneficial residual effect on succeeding wheat for subsequent two crop cycles. However, during third year, at par yield levels among studied treatments for both the crops indicated that residual effect of sub-soiling persisted no longer beyond two years. Better economic returns and consequently improved benefit: cost ratio clearly revealed that sub-soiling has economic benefits. Our studies concluded that sub-soiling exerted beneficial effect on soil physical properties by reduction in bulk density and improved infiltration rate and any sub-soiling either at 1.0 or 1.5 m once in three years has potential for improving productivity of cotton-wheat cropping system occupying 1.2 million ha in North-Western India.