scholarly journals Effects of interspecific competition on crop yield and nitrogen utilisation in maize-soybean intercropping system

Author(s):  
Liang Feng ◽  
Wen-Ting Yang ◽  
Quan Zhou ◽  
Hai-Ying Tang ◽  
Qiao-Ying Ma ◽  
...  

Intercropping system plays a crucial role in improving crop yield, nitrogen utilisation efficiency (NUE) and economic benefit. The difference in crop yield and interspecific relationship under different bandwidth and row ratio allocation patterns are still unclear. A field experiment was carried out to explore change regularities between crop yield and interspecific relationships under maize soybean intercropping with different bandwidths and row ratios. The results showed that the yield of intercropped crops was lower than that of the sole crop. The nitrogen accumulation (NA), NUE and nitrogen competition ratio was the highest under the intercropping mode with a bandwidth of 2.0 m, which indicated that this mode was more conducive to the N uptake and utilisation in crops. In all intercropping systems, nitrogen equivalent ratio (NER) and land equivalent ratio (LER) were all greater than one, indicating that intercropping systems were conducive to improving land utilisation efficiency and NUE. Under the same bandwidth pattern, expanding the maize soybean row ratio from 2 : 4 to 3 : 4 was beneficial to the improvement of LER, NER, NUE, crop group yield. In conclusion, it was preferable in the NA, NUE, crop group yield under the system of bandwidth 2.0 m and row ratio 2 : 2, which could be a reference for maize soybean intercropping system.

1989 ◽  
Vol 25 (4) ◽  
pp. 529-540 ◽  
Author(s):  
J. T. Russell ◽  
R. M. Caldwell

SUMMARYA field study was conducted in 1985 at two locations in Maryland, USA, to test the influence of environment (location), input level (N fertilization), management (component density combinations), and measure of performance on recommendations for a maize/soyabean intercrop. Location affected the degree of intercrop yield depression of each crop; the effect of N on relative competitive abilities; the maximum Land Equivalent Ratio (LER) and maximum modified Staple Land Equivalent Ratio (SLER); the difference between LER and SLER; the optimum density combinations and change in optima in response to N; and the N level at which the greatest land use efficiency was achieved. Given the complexity of the environmental effects, recommendations based on the trials have a very narrow range of applicability.


1980 ◽  
Vol 16 (1) ◽  
pp. 29-39 ◽  
Author(s):  
M. R. Rao ◽  
R. W. Willey

SUMMARYVarious intercrops were examined in an alternate row pattern with pigeonpea or sorghum on both Alfisol (red soil) and Vertisol (black soil). The slow-establishing and later-maturing pigeonpea combined well with earlier cereals and legumes to give very large yield advantages as measured by the Land Equivalent Ratio. In the pigeonpea/cereal combinations, the earlier the cereal the bigger the yield advantage tended to be, attributed to improved use of resources over time as the difference in maturity periods of the component crops increased. Sorghum was generally more competitive than pigeonpea and intercropping advantages tended to be less. But even where there was little difference in maturity periods of the component crops, both sorghum/legume and sorghum/cereal combinations gave substantial and statistically significant advantages, suggesting that improved ‘spatial’ use of resources was also important.


1990 ◽  
Vol 26 (2) ◽  
pp. 213-220
Author(s):  
B. A. Oyejola

SUMMARYWhen an intercrop fails to produce a required proportion of the sole crop yield, but produces a yield advantage over the sole crop, the method of sole crop supplementation has been suggested by many authors including Mead and Willey (1980) and Riley (1985). Modifications to the Land Equivalent Ratio (LER), used for assessing yield advantages, have been suggested and referred to as staple LERs (SLERs) and Effective LERs (ELERs). In this paper, a graphical method of estimating the SLER and ELER values (and consequently their yield advantages) is presented. The graphical estimation of the confidence interval for the SLER and ELER values is also shown.


Biochar ◽  
2021 ◽  
Author(s):  
Jing Peng ◽  
Xiaori Han ◽  
Na Li ◽  
Kun Chen ◽  
Jinfeng Yang ◽  
...  

AbstractCombined application of biochar with fertilizers has been used to increase soil fertility and crop yield. However, the coupling mechanisms through which biochar improves crop yield at field scale and the time span over which biochar affects carbon and nitrogen transformation and crop yield are still little known. In this study, a long-term field trial (2013–2019) was performed in brown soil planting maize. Six treatments were designed: CK—control; NPK—application of chemical fertilizers; C1PK—low biochar without nitrogen fertilizer; C1NPK, C2NPK and C3NPK—biochar at 1.5, 3 and 6 t ha−1, respectively, combined with chemical fertilizers. Results showed that the δ15N value in the topsoil of 0–20 cm layer in the C3NPK treatment reached a peak of 291 ‰ at the third year (2018), and demonstrated a peak of 402 ‰ in the NPK treatment in the initial isotope trial in 2016. Synchronously, SOC was not affected until the third to fourth year after biochar addition, and resulted in a significant increase in total N of 2.4 kg N ha−1 in 2019 in C3NPK treatment. During the entire experiment, the 15N recovery rates of 74–80% were observed highest in the C2NPK and C3NPK treatments, resulting in an annual increase in yields significantly. The lowest subsoil δ15N values ranged from 66‰ to 107‰, and the 15N residual rate would take 70 years for a complete decay to 0.001% in the C3NPK. Our findings suggest that biochar compound fertilizers can increase C stability and N retention in soil and improve N uptake by maize, while the loss of N was minimized. Biochars, therefore, may have an important potential for improving the agroecosystem and ecological balance. Graphic abstract


Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 343
Author(s):  
Anna Lavery ◽  
Conrad Ferris

The efficiency with which dairy cows convert dietary nitrogen (N) to milk N is generally low (typically 25%). As a result, much of the N consumed is excreted in manure, from which N can be lost to the environment. Therefore there is increasing pressure to reduce N excretion and improve N use efficiency (NUE) on dairy farms. However, assessing N excretion and NUE on farms is difficult, thus the need to develop proximate measures that can provide accurate estimates of nitrogen utilisation. This review examines a number of these proximate measures. While a strong relationship exists between blood urea N and urinary N excretion, blood sampling is an invasive technique unsuitable for regular herd monitoring. Milk urea N (MUN) can be measured non-invasively, and while strong relationships exist between dietary crude protein and MUN, and MUN and urinary N excretion, the technique has limitations. Direct prediction of NUE using mid-infrared analysis of milk has real potential, while techniques such as near-infrared spectroscopy analysis of faeces and manure have received little attention. Similarly, techniques such as nitrogen isotope analysis, nuclear magnetic resonance spectroscopy of urine, and breath ammonia analysis may all offer potential in the future, but much research is still required.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Song Chen ◽  
Xiaoguo Zhang ◽  
Xia Zhao ◽  
Danying Wang ◽  
Chunmei Xu ◽  
...  

The effects of night temperature on plant morphology and nitrogen accumulation were examined in rice (Oryza sativaL.) during vegetative growth. The results showed that the shoot biomass of the plants was greater at 27°C (high nighttime temperature, HNT) than at 22°C (CK). However, the increase in both shoot and root biomasses was not significant under 10 mg N/L. The shoot nitrogen concentrations were 16.1% and 16.7% higher in HNT than in CK under 160 and 40 mg N/L. These results suggest that plant N uptake was enhanced under HNT; however, the positive effect might be limited by the N status of the plants. In addition, leaf area, plant height, root maximum length, root and shoot nitrogen concentrations, soluble leaf protein content, and soluble leaf carbohydrate content were greater in HNT than in CK under 40 and 160 mg N/L, while fresh root volume, root number, and the content of free amino acid in leaf were not significantly different between HNT and CK regardless of nitrogen levels. Moreover, leaf GS activity under HNT was increased at 160 mg N/L compared with that under CK, which might partly explain the positive effect of HNT on soluble protein and carbohydrate content.


2004 ◽  
Vol 84 (4) ◽  
pp. 421-430 ◽  
Author(s):  
Y. K. Soon ◽  
M. A. Arshad

A field study was conducted to determine the effects and interactions of crop sequence, tillage and residue management on labile N pools and their availability because such information is sparse. Experimental treatments were no-till (NT) vs. conventional tillage (CT), and removal vs. retention of straw, imposed on a barley (Hordeum vulgare L.)-canola (Brassica rapa L.)-field pea (Pisum sativum L.) rotation. 15N-labelling was used to quantify N uptake from straw, below-ground N (BGN), and fertilizer N. Straw retention increased soil microbial biomass N (MBN) in 2 of 3 yr at the four-leaf growth stage of barley, consistent with observed decreases in extractable soil inorganic N at seeding. However, crop yield and N uptake at maturity were not different between straw treatments. No tillage increased soil MBN, crop yield and N uptake compared to CT, but had no effect on extractable soil inorganic N. The greater availability of N under NT was probably related to soil moisture conservation. Tillage effects on soil and plant N were mostly independent of straw treatment. Straw and tillage treatments did not influence the uptake of N from its various sources. However, barley following pea (legume/non-legume sequence) derived a greater proportion of its N from BGN (13 to 23% or 9 to 23 kg N ha-1) than canola following barley (nonlegumes) (6 to 16% or 3 to 9 kg N ha-1). Fertilizer N constituted 8 to 11% of barley N uptake and 23 to 32% of canola N uptake. Straw N contributed only 1 to 3% of plant N uptake. This study showed the dominant influence of tillage on N availability, and of the preceding crop or cropping sequence on N uptake partitioning among available N sources. Key words: Crop residue, crop sequence, labile nitrogen, nitrogen uptake, pea, tillage


2015 ◽  
Vol 12 (2) ◽  
pp. 52-62 ◽  
Author(s):  
VK Choudhary

Maize (Zea mays L.) being a widely space crop were tried with different combinations of legumes cowpea (Vigna unguiculata L. Walp), frenchbean (Phaseolus vulgaris L.) and blackgram (Vigna mungo L.) as intercrops at different planting geometry to find out their suitability during 2009, 2010 and 2011 at eastern Himalayan, Arunachal Pradesh, India. Three experiments were carried out in sequence to identify suitable planting geometry to accommodate intercrops, screening best legume crops and subsequently best performed row ratio of maize and legume crops were intercropped in third experiment with 1:1, 1:2 and 1:5 row proportions. Sole maize gave the maximum grain yield with 4571.1 kg ha-1, whereas, stover yield was highest with maize-cowpea intercrop at 1:2 row ratios (8013.4 kg ha-1) and 57.1 kg ha-1 day-1 production efficiency followed by frenchbean and least with blackgram. Competition indices like land equivalent ratio (LER) was highest with 1:2 row ratio of maize-frenchbean (1.66), land equivalent coefficient (0.67). But, highest area time equivalent ratio (ATER) noticed with 1:2 row ratio of maizeblackgram (1.47). Relative crowding coefficient (K) and competition ratio were noticed higher with 1:2 row ratio of maize-cowpea, whereas, cowpea combinations has better crowding coefficient and blackgram combinations registered better competitiveness. Monetary advantage index (MAI) was 6433.2 with 1:2 row ratio of maize-blackgram followed by maize-cowpea and lowest with maize-frenchbean with the trend of 1:2>1:5>1:1 row ratios. DOI: http://dx.doi.org/10.3329/sja.v12i2.21916 SAARC J. Agri., 12(2): 52-62 (2014)


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