scholarly journals Contribution of corn intercropped with Brachiaria species to nutrient cycling1

Author(s):  
Silas Maciel de Oliveira ◽  
Rodrigo Estevam Munhoz de Almeida ◽  
Clovis Pierozan Junior ◽  
André Fróes de Borja Reis ◽  
Lucas Freitas Nogueira Souza ◽  
...  

ABSTRACT The corn biomass and nutrient dynamics may be altered when it is intercropped with Brachiaria (syn. Urochloa spp.). The present study aimed to investigate the dynamics of biomass, nitrogen (N), phosphorus (P) and potassium (K) for farming systems that produce corn intercropped with Brachiaria species. Field experiments were performed during the season and off-season, in a split-plot design. The main plots were composed of Brachiaria species (B. brizantha,B. ruziziensis and B. Convert) intercropped with corn, in addition to corn monocropping. The subplots consisted of three forage sampling periods, ranging from 0 to 60 days after the corn harvest. The intercropping arrangements did not affect the corn grain yield, nutrient accumulation and partitioning, relatively to the corn monocropping. After the grain harvest, B. brizantha achieved the greater biomass accumulation rate in both the season (69 kg ha-1 day-1) and off-season (17 kg ha-1 day-1). The nutrient accumulation ranged widely between the Brachiaria species and planting seasons: 0.2-1.2 kg ha-1 day-1 for N; 0.01-0.07 kg ha-1 day-1 for P; and 0.13-0.8 kg ha-1 day-1 for K. However, the greatest nutrient accumulation was found for B. brizantha, followed by B. ruziziensis and then B. Convert. In the short-term, corn intercropped with Brachiaria in the season showed the largest effect on the nutrient cycling and biomass yield. The intercropping between corn and B. brizantha in the season was the best way to enhance the biomass yield and the N, P and K cycling.

Agronomy ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 500 ◽  
Author(s):  
Aziz Khan ◽  
Xiangjun Kong ◽  
Ullah Najeeb ◽  
Jie Zheng ◽  
Daniel Kean Yuen Tan ◽  
...  

High input costs combined with multiple management and material inputs have threatened cotton productivity. We hypothesize that this problem can be addressed by a single fertilization at flowering with late sowing in a moderately populated plant stand. Field experiments were conducted to evaluate the cotton biomass accumulation, phosphorus dynamics, and fiber quality under three planting densities (low, 3 × 104; moderate, 6 × 104; and dense, 9 × 104 ha−1) and two cultivars (Zhongmian-16 and J-4B). High planting density had 6.2 and 12.6% larger stems and fruiting nodes m−2, while low density produced a 37.5 and 59.4% maximum height node ratio. Moderate density produced 26.4–15.5%, 24.7–12.6%, and 10.5–13.6% higher biomass accumulation rate at the peak bloom, boll set, and plant removal stages over low and high density in both years, respectively. J-4B produced a higher reproductive organs biomass yield when compared with Zhongmian-16 in both years. This higher biomass formation was due to both the higher average (0.8 VT kg·ha−1·d−1) and maximum (1.0 VM kg·ha−1·d−1) reproductive organ phosphorus uptake, respectively. Plants with low density had 5.3–18.5%, 9.5–15%, and 7.8–12.8% greater length, strength, and micronaire values over moderate and dense plants, respectively. Conclusively, moderate density with J-4B is a promising option for improved biomass, phosphorus acquisition, and fiber quality under a short season.


2006 ◽  
Vol 86 (4) ◽  
pp. 1005-1014 ◽  
Author(s):  
S. S. Malhi ◽  
A. M. Johnston ◽  
J. J. Schoenau ◽  
Z. L. Wang ◽  
C. L. Vera

Dry matter and nutrient accumulation in the growing season are the main factors in the determination of seed yield and nutrient use efficiency. Field experiments were conducted with spring wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) and oat (Avena sativa L.) in 1998 and 1999 at Melfort, Saskatchewan, Canada, to determine the biomass accumulation and plant nutrient uptake at different growth stages, and their relationship with days after emergence (DAE) and growing degree days (GDD). All crops generally followed a similar pattern of biomass and nutrient accumulation in the growing season, which increased continuously with growing time, with much faster increase at early growth stages than at late growth stages. Maximum biomass accumulation rate and amount usually occurred at late boot stage (46–47 DAE or 443–460 GDD) and ripening stage (89–90 DAE or 948–1050 GDD), respectively. Maximum rate of nutrient uptake occurred at tillering to stem elongation stages (22–36 DAE or 149–318 GDD). Maximum amount of nutrient uptake generally occurred at the beginning of flowering to medium milk stages (61–75 DAE or 612–831 GDD), except for P in 1998 when it occurred at late milk to ripening stages (80–90 DAE or 922–1050 GDD). In general, the maximum nutrient uptake rate and amount, respectively, occurred earlier than maximum biomass accumulation rate and amount. For various cereal species/cultivars, maximum biomass accumulation rate was 204–232 kg ha-1 d-1, and maximum uptake rate of N, P, K and S, respectively, was 3.2–5.7, 0.30–0.60, 3.85–7.05 and 0.45–0.60 kg ha-1 d-1. The findings suggest that a sufficient supply of nutrients from soil and fertilizers at early growth stages is of great importance for optimum crop yield. Key words: Barley, biomass accumulation, cereals, growth stages, nutrient uptake, oat, wheat


2012 ◽  
Vol 52 (4) ◽  
pp. 381-396 ◽  
Author(s):  
Grzegorz Lemańczyk

Abstract Effects of agronomic practices on the occurrence of sharp eyespot and Rhizoctonia spp. in winter wheat were determined in two field experiments. In Experiment 1, in the village of Osiny, a comparison was made of disease in different farming systems. The farming systems were: organic, integrated, conventional, and monoculture. In Experiment 2, in the village of Mochełek, the effects of different chemical controls (no treatment, herbicide, herbicide + fungicide), mineral fertilizer doses (147 and 221 kg/ha NPK) and sowing densities (400 and 600 grains/m2) on the occurrence of sharp eyespot were compared in wheat grown in short-term monoculture. There was considerably more sharp eyespot in 2007 (disease index 1.63-29.5%) than in other years. Significant effects of the treatments were mostly noted at the milk ripe growth stage. The fewest sharp eyespot symptoms were seen in the integrated farming system. The most sharp eyespot symptoms were seen in the conventional and organic systems. There was a tendency for an increased intensity of symptoms in successive wheat-growing years of short-term monoculture. The application of pesticides showed no clear effect on the occurrence of sharp eyespot. The herbicide resulted in increased or decreased disease intensity depending on the cultivation year and the date of observation. Fungicide application did not decrease infection. Without chemical control, more symptoms were observed at the lower NPK rate. There were more symptoms at the higher sowing density. Stems with sharp eyespot symptoms were mostly infected by Rhizoctonia cerealis, and less frequently by R. solani. Binucleate Rhizoctonia spp., which could not be identified to species using polymerase chain reaction (PCR) techniques, were also recorded. Two R. zeae isolates were also obtained from stems with disease symptoms in Mochełek. R. solani was more often isolated from roots or stems with symptoms of true eyespot or fusarium foot rot. Most isolates of Rhizoctonia spp. were obtained at the milk ripe stage. A wheat-growing system and chemical control did not greatly affect the frequency of Rhizoctonia spp.


2016 ◽  
Vol 46 (3) ◽  
pp. 292-300 ◽  
Author(s):  
Adriano Stephan Nascente ◽  
Maria da Conceição Santana Carvalho ◽  
Paulo Holanda Rosa

ABSTRACT There is a lack of researches that evaluate the development and nutrient accumulation in super early genotypes of common bean for the elaboration of fertilization programs. This study aimed at characterizing the development; N, P, K, Ca and Mg accumulation by leaves; grain yield; and yield components of super early genotypes of common bean. Field experiments were conducted in a randomized blocks design, with four replications. The treatments consisted of the IPR Colibri (control), CNFC 15873, CNFC 15874 and CNFC 15875 genotypes. Plants were sampled throughout the common bean development, being divided into leaves, stems and pods. After determining the dry matter, the contents of N, P, K, Ca and Mg accumulated in leaves were estimated. At harvesting, the grain yield and yield components were evaluated. The biomass accumulation in stems and leaves occurred until the flowering stage, and then it started in the pods until harvesting. The genotypes that absorbed more nitrogen and phosphorus had a higher grain yield. The average growing season of super early genotypes was 70 days (winter) and 63 days (summer). CNFC 15874 was the most productive genotype in the winter, with grain yield similar to the IPR Colibri cultivar (control). In the summer, CNFC 15873 and CNFC 15875 achieved grain yield similar to the IPR Colibri cultivar.


2013 ◽  
Vol 33 (4) ◽  
pp. 699-708 ◽  
Author(s):  
Mariana M. Corradi ◽  
Alan R. Panosso ◽  
Marcílio V. Martins Filho ◽  
Newton La Scala Junior

The proper management of agricultural crop residues could produce benefits in a warmer, more drought-prone world. Field experiments were conducted in sugarcane production areas in the Southern Brazil to assess the influence of crop residues on the soil surface in short-term CO2 emissions. The study was carried out over a period of 50 days after establishing 6 plots with and without crop residues applied to the soil surface. The effects of sugarcane residues on CO2 emissions were immediate; the emissions from residue-covered plots with equivalent densities of 3 (D50) and 6 (D100) t ha-1 (dry mass) were less than those from non-covered plots (D0). Additionally, the covered fields had lower soil temperatures and higher soil moisture for most of the studied days, especially during the periods of drought. Total emissions were as high as 553.62 ± 47.20 g CO2 m-2, and as low as 384.69 ± 31.69 g CO2 m-2 in non-covered (D0) and covered plot with an equivalent density of 3 t ha-1 (D50), respectively. Our results indicate a significant reduction in CO2 emissions, indicating conservation of soil carbon over the short-term period following the application of sugarcane residues to the soil surface.


Plant Disease ◽  
1999 ◽  
Vol 83 (8) ◽  
pp. 733-738 ◽  
Author(s):  
J. P. Wilson ◽  
R. N. Gates

The expression of partial resistance to Puccinia substriata var. indica and its contribution to digestible biomass production in forage pearl millet hybrids were evaluated in field experiments at Tifton, GA. Inbreds Tift 383, Tift 65, and nine inbreds with partial resistance selected from the cross Tift 383 × ‘ICMP 501’ were crossed to Tift 23DA4. The parental inbreds and hybrids were evaluated in natural epidemics in 1996 and 1997. Because of maturity differences among the lines, slope of the regression of logit rust severity on time (apparent infection rate) and area under the disease progress curve (AUDPC) calculated for a defined interval of plant growth (10 days before to 20 days after anthesis) and adjusted for initial rust severity at 10 days prior to anthesis were the most useful indicators of resistance. Inbred resistance was not a reliable predictor of hybrid resistance when evaluated by either variable. Hybrids were evaluated for biomass production in 1996 and 1997 in a split-plot design, with hybrids as main plots and nontreated or chlorothalonil fungicide-treated as subplots. Differences existed among hybrids for AUDPC and for digestible dry matter yield (DDMY) and its components. Over all hybrids, the response between DDMY and final rust severity was described by logarithmic regression. Two clusters of hybrids were identified by cluster analysis of disease-related data from both experiments. The cluster of susceptible hybrids tended to have a lower DDMY and were less stable over year × treatment environments than the cluster of partially resistant hybrids. Lodging in nontreated plots in 1997 primarily occurred in susceptible hybrids. Although resistance was expressed in certain hybrids, greater levels of partial resistance are needed to provide adequate protection against DDMY losses.


2020 ◽  
Vol 12 (6) ◽  
pp. 23
Author(s):  
Yuxin He ◽  
Chao Liu ◽  
Heping Xie ◽  
Jingchen Wang ◽  
Yang Wang ◽  
...  

Agriculture is a crucial area to be considered when exploring and exploiting the use of deep-underground space. We investigated the feasibility of deep-underground seed storage by keeping canola seed in either envelopes or sealed packages at four depths below the Earth’s surface (0, 240, 690, and 1410 m) at a gold mine in northeastern China. We studied the effects of storage depth and duration by conducting germination tests with the stored seed. The results showed that the rate of germination was reduced in seed stored at deeper levels and was also lower at all depths after a more prolonged period of storage. Seeds from sealed packages exhibited better resistance to the deep-underground environment than seeds kept in envelopes. However, measurements of hypocotyl lengths and biomass accumulation revealed that the germination of seeds stored in deep-underground was initially inhibited but recovered well compared with the control as the storage depth increased. The total biomass of the hypocotyl increased as the depth of seed storage deepened, indicating the existence of a compensatory effect on seed germination. The findings suggest that short-term deep-underground storage of seeds in sealed packages would improve the germination performance of cultivated canola in terms of the hypocotyl length and biomass accumulation and might be considered as a pre-sowing strategy.


2019 ◽  
Author(s):  
Hongying Yu ◽  
Zhenzhu Xu ◽  
Guangsheng Zhou ◽  
Yao Shou

Abstract. Climate change severely impacts grassland carbon cycling, especially in arid ecosystems, such as desert steppes. However, little is known about the responses of soil respiration (Rs) to different warming magnitudes and watering pulses in situ in desert steppes. To examine their effects on Rs, we conducted long-term moderate warming, short-term acute warming and watering field experiments in a desert grassland of Northern China. While experimental warming significantly reduced Rs by 32.5 % and 40.8 % under long-term and moderate and short-term and acute warming regimes, respectively, watering pulses stimulated it substantially. Warming did not change the exponential relationship between Rs and soil temperature, whereas the relationship of Rs with soil water content (SWC) was well fitted to the Gompertz function. The soil features were not significantly affected by either long-term or short-term warming regimes, respectively; however, soil organic carbon content tended to decrease with long-term climatic warming. This indicates that soil carbon release responses strongly depend on the duration and magnitude of climatic warming, which may be driven by SWC and soil temperature. The results of this study highlight the great dependence of soil carbon emission on warming regimes of different durations and the important role of precipitation pulse during growing season in assessing the terrestrial ecosystem carbon balance and cycle.


2003 ◽  
Vol 11 ◽  
pp. 7-12
Author(s):  
C.D. Brown ◽  
R.B. Green

The dryland regions of New Zealand suffer from summer moisture deficits in the majority of years. These dryland regions have been developed along the same basis as other farming regions, with increasing fertiliser usage leading to more subdivision and higher stocking rates. Given the exposure to droughts, the production per head of these regions has been extremely variable. Historically, dryland farming systems have been based around breeding ewe systems with all lambs finished if the season allowed. Since the removal of all Government support during adverse events, in the early 1990s, farm systems have become considerably more diverse. Irrigation areas have doubled between 1985 and 1999 to approximately 500 000 hectares. Both sub clover and lucerne have been used extensively in dryland areas, but the main legume is still white clover. Farmers recognise the significant limitations in the ability of white clovers to cope with summer droughts, but have not been able to efficiently utilise other legumes, which require unique management to perform. There are a number of reasons for this. Looking forward, the five key roles that legumes have in dryland farming systems are, to persist within a general purpose pasture, to produce nitrogen, to improve summer feed quality, to improve year round quality feed through specialist crops and pastures and to provide specialist composite feeds (i.e. condensed tannins). With the increased diversity in farming systems, growers require a more diverse range of legumes from perennial species to annuals that will fit a short-term high feed quality niche.


Atmosphere ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1179
Author(s):  
Darlena Caroline da Cruz Corrêa ◽  
Abmael da Silva Cardoso ◽  
Mariane Rodrigues Ferreira ◽  
Débora Siniscalchi ◽  
Pedro Henrique de Almeida Gonçalves ◽  
...  

The reduction in ammonia (NH3) losses from volatilization has significant implications in forage production. The objective of this study was to evaluate the impact of N fertilizers (urea, ammonium nitrate, and ammonium sulfate) and four doses (0, 90, 180 and 270 kg N ha−1) on N losses by NH3 volatilization, accumulation, and forage chemical composition of Urochloa brizantha cv Marandu. Two field experiments were conducted to measure NH3 losses using semi-open chambers. The forage accumulation and chemical composition were evaluated in the third experiment; the response variables included forage accumulation, crude protein (CP), and neutral detergent fiber (NDF). Compared to urea, ammonium nitrate and ammonium sulfate reduced NH3 losses by 84% and 87% and increased total forage accumulation by 14% and 23%, respectively. Forage accumulation rate and CP increased linearly with the N levels, while NDF contents decreased linearly with the N levels. In both experiments, NH3 losses and forage characteristics were different according to the rainfall pattern and temperature variations. Our results indicate that the use of nitric and ammoniacal fertilizers and the application of fertilizer in the rainy season constitute an efficient fertilizer management strategy to increase forage yield and decrease losses from volatilization of NH3.


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