Maize Shoot Biomass Research Articles

Root Growth Responses of Maize (Zea mays L.) and Soybean (Glycine max L.) to Soil Compaction and Fertilization in a Ferric Acrisol

Mechanical impedance to root growth is one of the most important factors determining root elongation and proliferation within a soil profile. Two pot experiments were conducted at the Department of Horticulture, KNUST, Kumasi, Ghana, to determine the impact of subsurface compaction and different fertilizer amendments on the root growth of maize (Zea mays L.) and soybean (Glycine max L.). The experiments were arranged in a factorial Completely Randomized Design (CRD) with three replications. Maize and soybean varieties, “Obaatanpa” and “Anidaso” were sown in 72 plastic buckets (36 for each crop) of 12 L volume filled with a Ferric Acrisol. The treatments were different levels of compaction, using bulk density as proxy – 1.3, 1.5 and 1.7 Mg m-3, and fertilizer amendments of 100% poultry manure (15 g/pot), 100% NPK fertilizer (2.89 g/pot) and 50% each of poultry manure (7.5 g/pot) and NPK fertilizer (1.45 g/pot). The highest root growth occurred in the uncompacted soil and along the periphery of the soil core. The applied soil amendments significantly increased the root penetration ratio (RPR) of both crops in relation to the control. The shoot biomass of both crops decreased with increasing soil bulk density. All the applied soil amendments significantly increased the shoot biomass of maize and soybean over the control. The magnitude of response of the crops to the soil amendments was greater in soybean than in maize.

Soil Compaction and Soil Amendments on the Growth and Biomass Yield of Maize (Zea mays L.) and Soybean (Glycine max L.)

Two factorial pot experiments arranged in a Completely Randomised Design (CRD) with three replications were carried out to assess the impact of different levels of soil compaction and fertilizer amendments on root growth and biomass yield of maize (Zea mays L.) and soybean (Glycine max L.) plants. The treatments were different rates of bulk densities – 1.3, 1.5 and 1.7 Mg m-3 and fertilizer amendments comprising 100% poultry manure (applied at 15 g/plant), 100% 15:15:15 NPK fertilizer (applied at 2.89 g/plant) and 50% rate each of poultry manure and NPK fertilizer (applied at 7.5 g poultry manure + 1.45 g NPK/plant), and control (no fertilizer amendments). Soil compaction reduced the heights of maize and soybean plants. Increasing soil compaction resulted in the accumulation of most of the root biomass in the uncompacted soil above the compacted layer. Application of soil amendments increased the relative root biomass of maize plants in the uncompacted soil, while that in the compacted soil was reduced. In the case of soybean plants, although the relative root biomass in the uncompacted soil was relatively greater than that of maize plants, application of soil amendments tended to slightly decrease the relative root biomass to that of the control. The shoot biomass of both crops decreased with increasing soil bulk density. All the applied soil amendments significantly increased the shoot biomass of maize and soybean plants over the control. The magnitude of response of the crops to the soil amendments was greater in soybean than in maize plants. Soil compaction and amendments significantly influenced root/shoot ratio of both crops. The root/shoot ratio decreased with increasing compaction from 1.3 to 1.5 Mg m-3, however, at 1.7 Mg m-3, the root/shoot ratio increased. The fertilizer amendments significantly influenced the root/shoot ratio of maize but not soybean plants. The fertilizer amendments increased the biomass of both roots and shoots, being higher in the former than in the latter. The fertilizer amendments x compaction interactions showed that the root/shoot ratio was influenced by the type of crop, and the confounding effects of factor interactions on the relative increases/decreases in shoot and root growth. Overall, soil compaction accounted for 52 to 100% of the variations in the magnitude of the measured parameters of maize plants, and 62 to 98% for soybean plants. The ideal bulk density for shoot biomass production of both crops should, therefore, be within the range of 1.3 – 1.5 Mg m-3. At soil bulk density of 1.5 Mg m-3 and above, soil amendment should be added to ameliorate the negative impact of soil compaction.

<b>Chromium accumulation in maize and cowpea after successive applications of composted tannery sludge

Chromium (Cr) accumulation in soil and plants has been reported after successive applications of tannery sludge, which is a matter of concern because Cr can promote environmental contamination and affect the food chain. In this study, we evaluated the growth of and Cr accumulation in maize and cowpea after seven years of consecutive applications of composted tannery sludge (CTS) under field conditions. The experiment consisted of application of CTS at five levels: 0 (control), 2.5, 5, 10, and 20 Mg ha -1 (dry basis). The growth of and Cr accumulation in maize and cowpea were evaluated at 75 and 65 days after plant emergence, respectively. CTS application increased the shoot biomass of maize and cowpea. Accumulation of Cr was similar for both plant species, with higher accumulation in roots. However, Cr accumulation in grains differed as the CTS doses increased; cowpea accumulated more Cr while maize did not accumulate more Cr in grains with higher CTS doses. In conclusion, application of CTS led to higher growth of maize and cowpea plants, and both species exhibited similar Cr accumulation in roots and shoots.

High C/N materials mixed with cattle manure as organic amendments to improve soil productivity and nutrient availability

Identification of organic materials, which can enrich the soil organic matter pool and improve the productivity of marginal lands, is a necessity in tropical countries. A study was conducted to comprehend the effect of organic materials of different quality on the soil carbon (C) pool size and N, P, K release from soil. Organic amendments (OA) with different complexities namely, cattle manure (CM), cattle manure-rice straw (CR), cattle manure-wood shavings (CW), and cattle manure-rice straw-wood shavings (CRW) mixtures as fresh (f) or incubated for two months (i), were used in a leaching column study, soil incubation experiment and greenhouse experiment using maize (Zea mays L.) as the test plant. The N, P and K release pattern from soil, soil organic matter content and biomass of maize in OA added soils compared to fertilizer-only (SF) and soil-only (S) treatments were determined. The nitrogen release and microbial activity were higher in fresh-OA added soils compared to other treatments. Phosphorous and K were higher in soils amended with incubated-OA than fresh-OA. The highest N, P and K release was obtained with CM-i, CRWi and CM-f, respectively. Shoot biomass of maize was enhanced by 20-40% with the application of incubated-OA compared to SF. The total soil organic C and active organic C ranged from 10.85 to 13.50 g/kg and 0.31 to 0.64 g/kg, respectively, with soils treated with OA showing significantly high values compared to the control. The organic amendments used as fresh or incubated materials, did not impede plant growth and generally maintained or improved the soil nutrient status and C pool. Incubating OA prior to application improved the nutrient availability in soil. Tropical Agricultural Research Vol. 25 (2): 201 – 213 (2014)

Accumulation of Hydrocarbons by Maize (Zea mays L.) in Remediation of Soils Contaminated with Crude Oil

This study has investigated the use of screened maize for remediation of soil contaminated with crude oil. Pots experiment was carried out for 60 days by transplanting maize seedlings into spiked soils. The results showed that certain amount of crude oil in soil (≤2 147 mg·kg−1) could enhance the production of shoot biomass of maize. Higher concentration (6 373 mg·kg−1) did not significantly inhibit the growth of plant maize (including shoot and root). Analysis of plant shoot by GC-MS showed that low molecular weight polycyclic aromatic hydrocarbons (PAHs) were detected in maize tissues, but PAHs concentration in the plant did not increase with higher concentration of crude oil in soil. The reduction of total petroleum hydrocarbon in planted soil was up to 52.21–72.84%, while that of the corresponding controls was only 25.85–34.22% in two months. In addition, data from physiological and biochemical indexes demonstrated a favorable adaptability of maize to crude oil pollution stress. This study suggested that the use of maize (Zea mays L.) was a good choice for remediation of soil contaminated with petroleum within a certain range of concentrations.

The ameliorating effects of biochar and compost on soil quality and plant growth on a Ferralsol

Deteriorating soil fertility and the concomitant decline in agricultural productivity are major concerns in many parts of the world. A pot experiment was conducted with a Ferralsol to test the hypothesis that application of biochar improves soil fertility, fertiliser-use efficiency, plant growth and productivity, particularly when combined with compost. Treatments comprised: untreated control; mineral fertiliser at rates of 280 mg nitrogen, 70 mg phosphorus and 180 mg potassium pot–1 (F); 75% F + 40 g compost pot–1 (F + Com); 100% F + 20 g willow biochar pot–1 (F + WB); 75% F + 10 g willow biochar + 20 g compost pot–1 (F + WB + Com); 100% F + 20 g acacia biochar pot–1 (F + AB); and 75% F + 10 g acacia biochar + 20 g compost pot–1 (F + AB + Com). Application of compost with fertiliser significantly increased plant growth, soil nutrient status and plant nutrient content, with shoot biomass (as a ratio of control value) decreasing in the order F + Com (4.0) > F + WB + Com (3.6) > F + WB (3.3) > F + AB + Com (3.1) > F + AB (3.1) > F (2.9) > control (1.0). Maize shoot biomass was positively significantly correlated with chlorophyll content, root biomass, plant height, and specific leaf weight (r = 0.99, 0.98, 0.96 and 0.92, respectively). Shoot and root biomass had significant correlations with soil water content, plant nutrient concentration, and soil nutrient content after harvesting. Principal component analysis (PCA) showed that the first component provided a reasonable summary of the data, accounting for ~84% of the total variance. As the plants grew, compost and biochar additions significantly reduced leaching of nutrients. In summary, separate or combined application of compost and biochar together with fertiliser increased soil fertility and plant growth. Application of compost and biochar improved the retention of water and nutrients by the soil and thereby uptake of water and nutrients by the plants; however, little or no synergistic effect was observed.

First evidence for a major cover crop effect on arbuscular mycorrhizal fungi and organic maize growth

Arbuscular mycorrhizal fungi are increasingly used in organic cropping systems to increase yields. Although cover crops are largely used in organic farming, there is little knowledge on the impact of cover crops on native mycorrhizal fungi. Here, we studied the effect of cover crop diversity on mycorrhizal colonization in subsequent organic maize cultivars differing in the level of genetic diversity. Experiments were conducted from 2010 to 2012 in a Mediterranean environment. First Indian mustard (Brassica juncea L. Czern.), hairy vetch (Vicia villosa Roth), a mix of seven cover crop species (Mix), and natural vegetation (Control) were cultivated as winter cover crops. Then, an organically and a conventionally bred maize hybrid and three organically bred composite cross populations were cultivated. Mycorrhizal propagule dynamics were measured. Results at juvenile stage show a higher mycorrhizal colonization in maize plants grown after hairy vetch, of 35.0 %, and Mix cover crops, of 29.4 %, compared to Indian mustard, of 20.9 %, and Control, of 21.3 %. The potential of soil mycorrhization decreased of 56.5 % following Indian mustard, higher than that of other cover crops, of 34.1–47.3 %. This finding could be explained by the release of isothiocyanates in soils. Moreover, maize shoot biomass, nitrogen, and phosphorus content across all maize genotypes at juvenile stage increased with mycorrhizal colonization. These findings provide the first evidence of the greater role played by cover crop identity in the enhancement of early mycorrhizal colonization of the subsequent crop and of soil mycorrhizal activity.

Dynamics of root length and distribution and shoot biomass of maize as affected by intercropping with different companion crops and phosphorus application rates

Maize-based intercropping, especially with legumes, can result in overyielding of the whole cropping system and lead to efficient utilization of soil phosphorus (P). Field experiments were conducted in 2010 and 2011 to investigate the mechanisms behind overyielding of maize via root length and distribution in intercropping systems and how P application and companion crops may influence the process. The main plots received P applications of 0, 40, and 80kgha−1 and the sub-plots comprised maize (Zea mays L.) intercropped with turnip (Brassica campestris L.), faba bean (Vicia faba L.), chickpea (Cicer arietinum L.), or soybean (Glycine max L.), and monocropped maize. At turnip harvest and maize at stem elongation, total root length, growth space and corresponding shoot biomass (on a per plant basis) of maize intercropped with turnip, faba bean and chickpea were suppressed, especially in maize/turnip intercropping. Roots of maize and associated crops can intermingle with each other and the stronger the associated roots, the more depressed will be the corresponding maize root development and shoot biomass. At faba bean and chickpea harvest and maize at tasseling, total root length, growth space and corresponding shoot biomass of intercropped maize recovered to the same values as monocropped maize on a per plant basis. At soybean harvest and maize at grain-filling stage, total root length, growth space and shoot biomass of maize intercropped with turnip, faba bean, chickpea and soybean surpassed those of monocropped maize and showed overyielding and later maturity phenomena until harvest on a per plant basis. Total root length of maize on a per plant basis in the top 100cm of the soil profile at stem elongation and in the top 30cm at grain-filling stage and the shoot biomass of maize from stem elongation to grain-filling stage and at harvest were sensitive to P application. There were no interactions between P application rate and cropping system. A ‘competition–recovery–overyielding’ process was found in the dynamics of root length, distribution and corresponding shoot biomass of maize intercropped with turnip, faba bean and chickpea and the dynamics of root length and distribution correlated well with the corresponding shoot biomass of maize.

Selection of rhizobacterial strains for suppression of germination of Striga hermonthica (Del.) Benth. seeds

Abstract Striga hermonthica (Del.) Benth. is an obligate root-parasitic flowering plant that severely threatens cereal production in sub-Saharan Africa. A potential biological control option for reduction of crop yield–loss within the season of application is the use of soil-borne antagonists of S. hermonthica seed. This study was aimed at selecting soil-borne fluorescent pseudomonad strains capable of suppressing germination of S. hermonthica seeds and consequently reducing parasitism and damage to maize. An in vitro screening procedure was developed and was used to evaluate 460 fluorescent pseudomonad isolates from naturally suppressive soils. This resulted in the identification of 15 Pseudomonas fluorescens/P. putida isolates that significantly inhibited germination of S. hermonthica seeds. In a pot experiment using steam-sterilized soil, there was a significant reduction in the number of S. hermonthica plants on maize grown from seeds that were inoculated with any of the 15 bacterial isolates. Inoculation of maize seed with six of these isolates resulted not only in a reduced number of S. hermonthica plants, but also in an increased maize shoot biomass compared with the check. When soils inoculated with these bacterial isolates were left dried for 5 weeks after maize harvest and then planted with a second maize crop, no reduction in S. hermonthica parasitism was observed. This suggested that the bacteria did not persist in the soil after the first crop of maize. These results suggest that saprophytic fluorescent pseudomonads have potential for biological control of S. hermonthica in maize and that periodic application of bacteria, perhaps through seed treatment, may be necessary for sustained control.

Fertility status of soils of the derived savanna and northern guinea savanna and response to major plant nutrients, as influenced by soil type and land use management

Although the fertility status of soils in the West African moist savanna is generally believed to be low, crop yields on farmers' fields vary widely from virtually nil to values near the potential production. The soil fertility status was evaluated for a number of farmers' fields selected at random in 2 villages (Zouzouvou and Eglime) representative for the derived savanna (DS) benchmark area and in 2 villages (Danayamaka and Kayawa) representative for the Northern Guinea savanna (NGS) benchmark area. The relation between soil fertility status and soil type characteristics and fertilizer use was explored. In an accompanying missing nutrient greenhouse trial, the most limiting nutrients for maize growth were determined. While soils in the DS villages were formed on different geological units, soils in the NGS villages could be differentiated according to their position on the landscape. Generally, soils in the DS contained a smaller amount of silt (104 vs. 288 g kg−1), a larger amount of sand (785 vs. 584 g kg−1), C (9.3 vs. 6.3 g kg−1), N (0.7 vs. 0.5 g kg−1), Olsen-P (10.7 vs. 5.4 mg kg−1), and had a higher CEC (7.0 vs. 4.8 cmolc kg−1) than soils in the NGS villages. The large silt content of the soils in the NGS is a reflection of the aeolian origin of the parent material. Within the benchmark areas, general soil fertility characteristics were similar in the villages in the NGS, except for a larger amount of particulate organic matter in Kayawa than in Danayamaka. This may also have led to a significantly larger amount of ammonium-N content in the 0–20 and 20–40 cm soil layers in Kayawa compared to Danayamaka (42 vs 24 kg N ha−1 in the 0–20 cm soil layer). Differences in topsoil soil characteristics between the DS villages were a reflection of differences in clay quality (kaolinitic vs. 2:1 clay minerals) of the parent material and past fertilizer use. The Olsen-P and exchangeable K contents were observed to increase with increased fertilizer application rate in both benchmarks, while fertilizer application rate had no significant effect on the organic C or total N content of the soil nor on its ECEC. The response of maize shoot biomass production to applied N was similar for both benchmarks (biomass accumulation in the treatment without N was, on average, 55% of the biomass production in the treatment which received all nutrients), while soils in the NGS responded more strongly to applied P than soils in the DS (37% vs 66% of biomass production in the treatment which received all nutrients). The more favourable P status of soils in Eglime (DS) was attributed to the more intense use of P fertilizers, as a result of government-supported cotton production schemes. Response to cations, S or micronutrients were neglegible. A significant linear relationship was found between the soil Olsen-P content and the response to applied P up to levels of 12 mg kg−1 in the topsoil. Above this level, a plateau was reached.

Nitrogen contribution of five leguminous trees and shrubs to alley cropped maize in Ibadan, Nigeria

There are abundant local legume trees and shrubs potentially suitable for alley cropping systems in the sub-Saharan Africa, which are yet to be studied. The nitrogen contribution of two years old Albizia lebbeck and S. corymbosato yield of maize grown in alley cropping was compared to that of Senna siamea, Gliricidia sepium and Leucaena leucocephala in four seasons at Ibadan. Maize shoot biomass and maize grain yield in A. lebbeck alley compared favourably with that in G. sepium and L. leucocephala. Maize biomass and grain yield in S. corymbosa alleys were the lowest. Within A. lebbeck, L. leucocpehala, and G. sepium alleys there were no significant differences in the maize yield in the alleys that received 0, 40 or 80 kg N/ha. Application of more than 40 kg N/ha in S. corymbosa alleys was not necessary as there was no significant increase in maize yield at the higher level of nitrogen. Maize yield and N uptake in A. lebbeck alleys were not significantly different from yield and N uptake in G. sepium, and L. leucocephala at the same fertilizer level. There was a significant correlation between hedgerow tree biomass and maize grain yield. At the end of twelve weeks after pruning application, the organic residues of the pruning applied in the alleys ranged from 5% in G. sepium and 44% in A. lebbeck in the first year compared with the original pruning applied which showed that the slow rate of A. lebbeck decomposition could have a beneficial effect on the soil. The maize N recovery from applied N fertilizer was low (10–22%). Percentage N recovery from the prunings was low in the non-N fixing trees (12–22%), while the recovery was high (49–59%) in A. lebbeck as well as in the other nitrogen fixing tree prunings. Thus A. lebbeck, apart from enhancing maize growth and grain yield like in L. leucocephala and G. sepium, had an added advantage because it remained longer as mulching material on the soil because of its slow rate of decomposition. It was able to survive pruning frequencies with no die-back. This indicates that A. lebbeck is a good potential candidate for alley cropping system in West Africa. S. corymbosa performed poorly compared with the other legume trees. Though it responded to N fertilizer showing a positive interaction between the hedgerow and fertilizer application, it had a high die back rate following pruning periods and termite attack.

Genotypic Variation in Maize Shoot Biomass at Different Stages of Development

AbstractA diallel cross from nine early‐maturing lines of maize was grown in northern Germany during 1981 and 1982 in order to study the genotypic variation of shoot biomass at early and late stages of development. Inbred lines had been chosen from breeding programmes for early and medium early cultivars. Nevertheless, the date of maturity varied between them which can have some influence on the correlation between plant parameters. Plants were harvested at the fourth and sixth leaf stages, at anthesis and at maturity. S.c.a. effects were highly significant for traits during the vegetative stage. G.c.a. effects were highly significant for traits of the mature plant including grain yield components. The ratio of g.c.a. to s.c.a. effects for shoot biomass was dominated throughout the growing season by s.c.a. effects. Hybrids from the diallel cross had a superior growth rate until the fourth leaf stage; thereafter, relative growth rates of lines and hybrids were similar for the average of both groups until maturity. The correlation of g.c.a. effects and s.c.a. effects between shoot biomass throughout the season revealed that no significant relationship existed between early and late stages. G.c.a. and s.c.a. effects for grain yield components, with the exception of hundred kernel weight, were negatively correlated with shoot biomass at an early stage while correlation was positive at maturity. This would probably make it a difficult task to improve shoot growth and grain yield components simultaneously through the season.