Years Of Maize Cultivation Research Articles

Effects of Different Fertilization Measures on Corn Yield and Soil Nitrogen Level in Hollow Village On the Loess Plateau

Problems of poor soil structure and nutrient deficiency in the reclamation of abandoned homesteads, and improvement of the soil condition after land reclamation to arable land and rapidly resume agricultural production were investigated. Organic fertilizers, curing agent and fly ash as amendment materials were selected. A plot test with seven different return materials in order to obtain the effects of different amendment materials on nutrient improvement in the reclamation of abandoned homestead soils in loess areas was conducted. After 3 years of maize crop cultivation, soil samples were collected and analyzed for total soil nitrogen content under different treatments. The results showed that the maize yield in each plot showed different additives contributed to the increase in maize yield to different degrees, while the addition of organic fertilizer had a more significant effect on the increase in yield. In the treatment of the experimental plots with the addition of curing agent + organic fertilizer, there was a significant effect on the enhancement of the content of total nitrogen in the soil tillage layer after three years of maize cultivation. The total N content of the surface soil (0~15 cm) increased from 0.32 to 0.64 g/kg, and that of the soil from 15~30 cm increased from 0.31 to 0.66 g/kg. The total N content of the soil from 0~60cm showed an increasing trend year by year, but the increase was gradually reduced. The total nitrogen content of soil in the depth of 60~105 cm showed a decreasing trend year by year. In the remediation of hollow villages in loess plateau, the compound application of organic fertilizer and ripening agent can significantly improve the soil nutrient content, condition of farmland and increase in maize yield, which is the most suitable material for field return in the remediation of hollow villages in loess plateau, and is of great significance to improve the quality of field return in the remediation of hollow villages. Bangladesh J. Bot. 50(3): 729-736, 2021 (September) Special

Linking land use patterns and pest outbreaks in Bt maize.

Western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is a major pest of maize in the United States and is an invasive pest in Europe. Maize is the only agricultural crop on which western corn rootworm larvae can survive and this insect requires two consecutive years of maize cultivation to complete its life cycle. Transgenic maize producing insecticidal proteins derived from the bacterium Bacillus thuringiensis (Bt) is often used to manage rootworm populations. The first Bt trait, Cry3Bb1, was introduced in 2003, but larval resistance to this toxin appeared in northeastern Iowa in 2009. Rootworm management occurs on a field-by-field basis, but adult rootworm may disperse among fields. It is known that growing consecutive years of Cry3Bb1 maize within a field can lead to resistance, but the relationship of the surrounding landscape to the development of resistance is unknown. Using geospatial tools and publicly available land-use data, we examined circular areas (buffers) surrounding fields that had previously experienced high levels of rootworm injury to Cry3Bb1 maize and rootworm resistance to Cry3Bb1 maize (problem fields). We calculated the proportion of area inside each buffer planted to maize continuously for 1-9 yr, and compared these values to those for randomly selected control points throughout the state. We also calculated the proportion of the state planted to maize for at least three consecutive years for 2003 through 2018, and its relationship with the annual value of maize. We found that areas surrounding problem fields had significantly more continuous maize compared to controls, with the most continuous maize within 1.6km of problem fields. We also found that the cultivation of continuous maize in Iowa increased significantly between 2003 and 2018, and this was correlated with average annual price of maize. We hypothesize a scenario in which continuous cultivation of Cry3Bb1 maize in local landscapes, driven in part by the increased value of maize, facilitated selection for Cry3Bb1 resistance. These results suggest that land use in areas surrounding problem fields affect the rate of resistance evolution and approaches for resistance management can be enhanced by taking a landscape-level perspective.

Differentiation of maize breeding samples by β-carotene content

Plant carotenoids are important micronutrients in the diet of humans and animals, since they act as precursors for the synthesis of vitamin A in animal cells. The most effective precursor to the vitamin A biosynthesis is β-carotene. Increasing the β-carotene content in maize grain as an important feed and food crop is an urgent task for plant selection. The purpose of this work was to differentiate maize breeding samples from the Dnipro breeding program by the β-carotene content in mature grain. Maize grain of 18 inbreds harvested in 2015 and 5 inbreds harvested in 2016 was researched. Determination of β-carotene content in matured dry grain was carried out after petroleum ether extraction and ultra performance liquid chromatography (UPLC) in the mobile phase of methanol/acetonitrile. The β-carotene content in the grain of genotypes from the Dnipro breeding program was on average 1.020 mg/kg for inbreds grown in 2015, and 0.672 mg/kg for inbreds grown in 2016. These values correspond to the β-carotene content in the grain of the majority of genotypes from world breeding programs selected by methods of classical selection. The inbred DKV3262 with white grain had the smallest content of β-carotene (0.076 mg/kg), while the yellow-coloured line DKD9066 had the highest one (2.146 mg/kg). The variation in the grain β-carotene content in different years of maize cultivation was noted. Inbreds of flint and semident maize showed the general tendency to increase the β-carotene content in grain compared with dent ones. The distribution of the studied inbreds on germplasm types showed the significant variation of β-carotene content in grain and the incidence of relatively high values in all germplasms analyzed. Inbreds containing more than 1.5 mg of β-carotene per 1 kg of grain, DK239, DK206A, DK212, DKD9066 and DKE-1, are emphasized as promising for the selection to increase the content of valuable micronutrients.

A 1,000-Year-Old RNA Virus.

Only a few RNA viruses have been discovered from archaeological samples, the oldest dating from about 750 years ago. Using ancient maize cobs from Antelope house, Arizona, dating from ca. 1,000 CE, we discovered a novel plant virus with a double-stranded RNA genome. The virus is a member of the family Chrysoviridae that infect plants and fungi in a persistent manner. The extracted double-stranded RNA from 312 maize cobs was converted to cDNA, and sequences were determined using an Illumina HiSeq 2000. Assembled contigs from many samples showed similarity to Anthurium mosaic-associated virus and Persea americana chrysovirus, putative species in the Chrysovirus genus, and nearly complete genomes were found in three ancient maize samples. We named this new virus Zea mays chrysovirus 1. Using specific primers, we were able to recover sequences of a closely related virus from modern maize and obtained the nearly complete sequences of the three genomic RNAs. Comparing the nucleotide sequences of the three genomic RNAs of the modern and ancient viruses showed 98, 96.7, and 97.4% identities, respectively. Hence, in 1,000 years of maize cultivation, this virus has undergone about 3% divergence.IMPORTANCE A virus related to plant chrysoviruses was found in numerous ancient samples of maize, with nearly complete genomes in three samples. The age of the ancient samples (i.e., about 1,000 years old) was confirmed by carbon dating. Chrysoviruses are persistent plant viruses. They infect their hosts from generation to generation by transmission through seeds and can remain in their hosts for very long time periods. When modern corn samples were analyzed, a closely related chrysovirus was found with only about 3% divergence from the ancient sequences. This virus represents the oldest known plant virus.

Effects of the ridge mulched system on soil water and inorganic nitrogen distribution in the Loess Plateau of China

The semi-arid region of the Loess Plateau is typical of rain-fed agricultural production in Northwestern China. In this area, the ridge mulched system (RM) is a widely-used measure to increase crop yield. The purpose of this study was to investigate the effect of RM on soil water and inorganic nitrogen (N) distribution, and grain yield of maize (Zea mays L.). The study was conducted over three consecutive years and consisted of four treatments (each replicated three times): i) RM with N application rate of 260 kg N ha−1 (RM-N260); ii) RM with 180 kg N ha−1 (RM-N180); iii) a traditional flat cultivation system without mulching (F) with 260 kg N ha−1 (F-N260); iv) F with 180 kg N ha−1 (F-N180). Mean soil water content during the maize growing season was increased by RM in 2013 only. However, RM increased the soil water storage significantly at the 3-leaf (V3) and 6-leaf stage (V6), and decreased evapotranspiration (ET) during pre-silking stage in all years. Compared to F, RM significantly improved maize grain yield by 79–123% in 2013, 23–25% in 2014, and 11–12% in 2015. Following three years of maize cultivation, soil inorganic N content increased substantially (two- to three-fold) in the RM system and 60% of the total inorganic N was accumulated in the top soil layers (0–60 cm) under the mulched ridge. Relative changes were much smaller in F, and most of inorganic N was stored in 0–20 cm and 100–160 cm soil layers. Generally, RM resulted in higher soil water storage during the pre-silking stage, which was the main reason for the improved maize grain yield. The nitrate leaching risk was reduced in RM-N180 compared with F, but nitrate leaching from the furrows between ridges was observed in RM-N260. However, the large increase in soil inorganic N content in RM-N180 after three years’ cultivation indicates an oversupply of N and a potential risk of N losses to the environment over the longer term. Our study indicates, therefore, that RM is a suitable system for maize cropping in the semi-arid region of the Loess Plateau, with benefits in water and N use efficiency, but recommendations for appropriate N application rates are required to ensure long term agricultural sustainability, accounting for grain yields and environmental impacts. The mechanisms for inorganic N accumulation under the RM system are not fully understood and warrant further investigation.

Does long-term plastic film mulching really decrease sequestration of organic carbon in soil in the Loess Plateau?

Abstract Plastic film mulching (PM) is used extensively in China to increase the productivity of food crops, especially in the arid and semi-arid regions, although a recent concern is whether the practice decreases soil organic carbon (SOC). A process-based biogeochemical model applied in the Loess Plateau, where PM is widespread, examined the status of SOC over 30 years of maize cultivation with PM. The model explained 96% of the observed variance in SOC. The root mean square error was 0.39 g kg −1 , the mean absolute error was 0.32 g kg −1 , and the bias value from the SOC simulation was −0.006 g kg −1 . The model’s projections showed that PM has no significant impact on the overall average content of SOC across the entire study area compared to the fields without mulching, or control (CK), assuming that 5% of the crop residue was ploughed back into soil. However, based on individual simulation points in the 0–50 cm soil profile after 30 years of PM, 59.29% of the points, mainly on the western parts of the Loess Plateau, showed significantly higher SOC than that in CK, 8.30% showed significantly lower, and 32.41%, mainly on the south-eastern part of the Plateau, showed no significant difference between sites with PM and without it. Mulching increased the biomass, rhizodeposition, and the speed of turnover of SOC significantly, compared to the corresponding values in CK. High biomass in PM led to more carbon (C) being retained in soil and lowered the depletion of SOC. Ploughing the crop residues back into soil increased SOC, the greater the percentage of residue thus returned to soil, the higher the SOC. For a given residue return percentage, PM could increase more SOC than the CK. At 15%, which is the current average residue return ratio in the Loess Plateau, SOC levels remained stable or even increased in 77% of the study area if it adopted PM; in CK, the corresponding figure was only 63%. In regions such as the Loess Plateau where biomass is in great demand as a fuel or animal feed, PM provides greater biomass, which also means that more of it is available to be returned to soil—PM thus promotes the sequestration of SOC.

Maize yield and water balance is affected by nitrogen application in a film-mulching ridge–furrow system in a semiarid region of China

Poor soil and drought stress are common in semiarid areas of China, but maize has a high demand for nitrogen (N) and water. Maize production using the technique of double ridges and furrows mulched with plastic film are being rapidly adopted due to significant increases in yield and water use efficiency (WUE) in these areas. This paper studied N use and water balance of maize crops under double ridges and furrows mulched with plastic-film systems in a semiarid environment over four growing seasons from 2007 to 2010. To improve precipitation storage in the non-growing season, the whole-year plastic-film mulching technique was used. There were six treatments which had 0, 70, 140, 280, 420 or 560kgNha−1 applied in every year for maize. In April 2011, spring wheat was planted in flat plots without fertilizer or mulch following four years of maize cultivation. After four years, all treatments not only maintained soil water balance in the 0–200cm soil layer but soil water content also increased in the 0–160cm soil layer compared to values before maize sowing in April 2007. However, under similar precipitation and only one season of spring wheat, soil water content in the 0–160cm soil layer sharply decreased in all treatments compared to values before sowing in April 2011. Over the four years of maize cultivation, average yield in all treatments ranged from 4071 to 6676kgha−1 and WUE ranged from 18.2 to 28.2kgha−1mm−1. In 2011, the yield of spring wheat in all treatments ranged from 763 to 1260kgha−1 and WUE from 3.5 to 6.5kgha−1mm−1. The potential maximum grain yield for maize was 6784kgha−1 with 360kgNha−1 applied for four years, but considerable NO3N accumulated in the soil profile. A lesser application (110kgNha−1) to this tillage system yielded in 82% of the maximum, increased nitrogen use efficiency and mitigated the risk of nitrogen loss from the system. This study suggests that double ridge–furrow and whole-year plastic-film mulching could sustain high grain yields in maize with approximately 110kgNha−1 and maintain soil water balance when annual precipitation is >273mm in this semiarid environment.

Nawożenie organiczne i mineralne kukurydzy kształtujące występowanie chorób fuzaryjnych (Fusarium spp.) oraz omacnicy prosowianki (Ostrinia nubilalis Hbn.)

Summary The aim of the study was to assess the consequent influence of one-time used full dose of manure after 10 years of maize cultivation in monoculture and diverse mineral fertilization NPK on health of maize plants. No significant influence of application of a full dose of manure on 10-year maize cultivation in monoculture on plant infestation with fungi of the genus Fusarium spp. and damages caused by Ostrinia nubilalis was found in subsequent years of the cultivation. Application of PK before sowing and N in the 5–6 leaf stage (BBCH 15–16) decreased plant health in comparison with objects where NPK was used before maize sowing. Plant infestation with fungi of the genus Fusarium spp. and damages caused by O. nubilalis increased in the subsequent years of maize cultivation in monoculture. A high positive coefficient of correlation between prevalence of European corn borer and maize plant infestation with fusarium diseases was demonstrated.

Ligno-aliphatic complexes in soils revealed by an isolation procedure: implication for lignin fate

For the last decades, the fate of lignins in soil was analyzed mainly with cupric oxide (CuO) oxidation, which is traditionally used to quantify soil lignin content and characterize its state of degradation. This method presents limitations due to incomplete depolymerization of the lignin structure. In this study, we used a physicochemical soil lignin isolation procedure, which permits recovery of a milled wall enzymatic lignin (MWEL) fraction. Elemental composition and chemical structure of MWEL isolated from plants and soil were characterized. Its incorporation rate into an agricultural loamy soil was studied using stable isotope analyses of MWEL isolated from soils after 0 to 9 years of maize cultivation after wheat. Comparison of MWEL isolated from maize tissues and soil provided information on evolution of the lignin structure once incorporated into soil. We observed aromatic–aliphatic complex formation, which could lead to its sequestration in soil evidenced by increasing MWEL content after 9 years of maize cultivation. The 13C natural abundance of isolated MWEL showed faster incorporation of MWEL (17.4 % of renewed lignins after 9 years) compared to total soil organic matter (9 % of total soil organic carbon (SOC) was renewed). This faster incorporation rate of MWEL compared to bulk soil organic matter is in agreement with lignin turnover observed by CuO oxidation. Radiocarbon dating of MWEL suggested a mean age of around 50 years. We conclude that lignin isolation allows (1) access to a different fraction compared to CuO oxidation and (2) a detailed characterization of lignin transformation in soil. We suggest that interaction with aliphatic compounds could be one possible pathway of lignin preservation in soil.

From ice age to modern: a record of landscape change in an Andean cloud forest

AbstractAim To investigate the palaeoecological changes associated with the last ice age, subsequent deglaciation and human occupation of the central Andes.Location Lake Pacucha, Peruvian Andes (13°36′26″ S, 73°19′42″ W; 3095 m elevation).Methods Vegetation assemblages were reconstructed for the last 24 cal. kyr bp (thousand calibrated 14C years before present), based on pollen analysis of sediments from Lake Pacucha. An age model was established using 14C accelerator mass spectrometry dates on bulk sediment. Fossil pollen and sedimentological analyses followed standard methodologies.Results Puna brava replaced the Andean forest at the elevation of Lake Pacucha at the Last Glacial Maximum (LGM). Deglaciation proceeded rapidly after 16 cal. kyr bp, and near‐modern vegetation was established by c. 14 cal. kyr bp. The deglacial was marked by the range expansion of forest taxa as grassland taxa receded in importance. The mid‐Holocene was marked by a lowered lake level but relatively unchanged vegetation. Quinoa and maize pollen were found in the latter half of the Holocene.Main conclusions Temperatures were about 7–8 °C colder than present at this site during the LGM. The pattern of vegetation change was suggestive of microrefugial expansion rather than simple upslope migration. The mid‐Holocene droughts were interrupted by rainfall events sufficiently frequent to allow vegetation to survive largely unchanged, despite lowering of the lake level. Human activity at the lake included a 5500‐year history of quinoa cultivation and 3000 years of maize cultivation.

Effects of earthworm inoculation on soil organic matter dynamics of a cultivated ultisolThe 7th international symposium on earthworm ecology · Cardiff · Wales · 2002

Summary In Peruvian Amazonia, cropping techniques manipulating the biological processes of soil fertility have been tested to increase productivity and sustainability of crops. Special attention was paid to earthworms since their communities are dominant in natural ecosystems and severely depleted in cultivated soils, and also because their populations can be manipulated. The objective of this work was to evaluate the impact of the endogeic earthworm Pontoscolex corethrurus on soil organic matter dynamics, by comparing treatments with and without earthworms. Carbon dynamics is described using particle-size fractionation and in situ natural isotopic labelling (carbon 13) obtained by shift of C3 to C4 vegetation. After 6 years of maize cultivation, the organic carbon stock of the 0–10 cm layer decreased respectively by 4 and 27% in the control and the earthworm inoculated treatments. For the inoculated treatment this decrease mainly occurred in the large particle size (plant residues). Seventy % of the carbon derived from forest was lost during 6 years in the 2000–200 μm fractions in the inoculated treatment and 19% in the control. However, the incorporation of carbon derived from maize in soil, especially in the large particle fractions (>50 μm), was lower in the earthworm inoculated treatment. Accordingly, the proportions of carbon derived from forest and from maize were the same in the two treatments. Thus, the main effect of earthworm inoculation was a more important mineralisation of the carbon derived from forest and maize, especially in the large particle size fractions (>50 μm).

Effects of earthworm inoculation on soil organic matter dynamics of a cultivated ultisol: The 7th international symposium on earthworm ecology · Cardiff · Wales · 2002

In Peruvian Amazonia, cropping techniques manipulating the biological processes of soil fertility have been tested to increase productivity and sustainability of crops. Special attention was paid to earthworms since their communities are dominant in natural ecosystems and severely depleted in cultivated soils, and also because their populations can be manipulated. The objective of this work was to evaluate the impact of the endogeic earthworm Pontoscolex corethrurus on soil organic matter dynamics, by comparing treatments with and without earthworms. Carbon dynamics is described using particle-size fractionation and in situ natural isotopic labelling (carbon 13) obtained by shift of C3 to C4 vegetation. After 6 years of maize cultivation, the organic carbon stock of the 0–10 cm layer decreased respectively by 4 and 27% in the control and the earthworm inoculated treatments. For the inoculated treatment this decrease mainly occurred in the large particle size (plant residues). Seventy % of the carbon derived from forest was lost during 6 years in the 2000–200 μm fractions in the inoculated treatment and 19% in the control. However, the incorporation of carbon derived from maize in soil, especially in the large particle fractions (>50 μm), was lower in the earthworm inoculated treatment. Accordingly, the proportions of carbon derived from forest and from maize were the same in the two treatments. Thus, the main effect of earthworm inoculation was a more important mineralisation of the carbon derived from forest and maize, especially in the large particle size fractions (>50 μm).

13C Labelling of soil n-hentriacontane (C 31) by maize cultivation

The fate of plant carbon into molecular organic substances from soils can be followed by stable carbon analysis. Soil organic matter has thus been progressively labelled with 13C at natural abundance by cultivation of Zea mays, a C 4 plant, on a soil which was previously under isotopically distinct C 3 vegetation. The molar carbon percentage of maize n-hentriacontane within soil n-hentriacontane has been calculated by isotopic means and amounts to around 50% after 23 years of maize cultivation.