A simple method to improve the estimation of the relationship between rainfall and crop yield

2007 ◽  
Vol 27 (3) ◽  
pp. 255-260 ◽  
Author(s):  
Andrea Monti ◽  
Gianpietro Venturi

2020 ◽  
Vol 4 (2) ◽  
pp. 780-787
Author(s):  
Ibrahim Hassan Hayatu ◽  
Abdullahi Mohammed ◽  
Barroon Ahmad Isma’eel ◽  
Sahabi Yusuf Ali

Soil fertility determines a plant's development process that guarantees food sufficiency and the security of lives and properties through bumper harvests. The fertility of soil varies according to regions, thereby determining the type of crops to be planted. However, there is no repository or any source of information about the fertility of the soil in any region in Nigeria especially the Northwest of the country. The only available information is soil samples with their attributes which gives little or no information to the average farmer. This has affected crop yield in all the regions, more particularly the Northwest region, thus resulting in lower food production.  Therefore, this study is aimed at classifying soil data based on their fertility in the Northwest region of Nigeria using R programming. Data were obtained from the department of soil science from Ahmadu Bello University, Zaria. The data contain 400 soil samples containing 13 attributes. The relationship between soil attributes was observed based on the data. K-means clustering algorithm was employed in analyzing soil fertility clusters. Four clusters were identified with cluster 1 having the highest fertility, followed by 2 and the fertility decreases with an increasing number of clusters. The identification of the most fertile clusters will guide farmers on where best to concentrate on when planting their crops in order to improve productivity and crop yield.



1972 ◽  
Vol 8 (4) ◽  
pp. 311-314 ◽  
Author(s):  
T. M. Lim ◽  
R. Narayanan

SUMMARYA rapid, simple method is described for estimating the area of rubber leaves from two measurements on the middle and one of the side leaflets. The relationship between the area of a leaflet (A) and its length × breadth (LB), described by the expression A = 0.654 LB, does not vary between the three leaflets or between leaves of different ages, and clonal differences are slight.



Author(s):  
Mohammad S. Khrisat ◽  
Ziad A. Alqadi

<span>Multiple linear regressions are an important tool used to find the relationship between a set of variables used in various scientific experiments. In this article we are going to introduce a simple method of solving a multiple rectilinear regressions (MLR) problem that uses an artificial neural network to find the accurate and expected output from MLR problem. Different artificial neural network (ANN) types with different architecture will be tested, the error between the target outputs and the calculated ANN outputs will be investigated. A recommendation of using a certain type of ANN based on the experimental results will be raised.</span>



2016 ◽  
Vol 8 (1) ◽  
pp. 20 ◽  
Author(s):  
M. Bänziger ◽  
G. O. Edmeades ◽  
J. Bolaños

The amount of dry matter produced during various stages of corn growth is a important variable to be taken into consideration. However, the lack of drying facilities makes its measurement a difficult task in the fields. A simple method to convert the fresh weight of a crop in the field into dry weight, could be an answer to that problem. In this study, we calculated the relationship between fresh and dry weight of corn stovers, over several, growth, stages of eight corn cultivars of different vigour and maturity period, at two Mexican locations. The differences between cultivars were for percent stover dry weight (%SDW) most evident in the second half of the grain growth stage, when late cultivars showed less humidity than the early ones. The % SDW was regressed against the phenological developmental stage and expressed as a ratio against antesis (R, days to sampling /days to 50% antesis). The equations (R2 = 0.97 - 0.99) with best results were: Early maturing cultivars: %SDW = 12.6 + 0.94R2 + 1.68R4; Late: %SDW = 16.1 - 4.00 R2 + 3.36R4. There were no consistant differences among cultivars with different vigour levels, even though certain differences were noted among the locations and they were attributed to differences in relative humidity. We describe a protocol for determining the dry weight of corn stover by area unit (t/ha) when drying conditions are not available, by utilizing only a scale and a ruler.We also suggest a method to calculate percent dry matter for a real plant parts (including grain).



Nature ◽  
1928 ◽  
Vol 122 (3068) ◽  
pp. 258-258
Author(s):  
E. V. N.


1958 ◽  
Vol 1958 ◽  
pp. 19-29 ◽  
Author(s):  
Alan Robertson ◽  
S. S. Khishin

The past few years have seen the development in Great Britain of the ‘contemporary comparison’ method for evaluating progeny tests of dairy sires (Macarthur, 1954; Robertson, Stewart and Ashton 1956). The final overall figure attached to a sire is the mean difference between the yield of his daughters and that of other heifers milking in the same herd in the same year, with due regard for the numbers of animals in the two groups. Although it has some imperfections in special cases, this is probably the most informative simple method of evaluating a sire for yield and, fortunately, one which could be easily integrated with the existing recording system. The method has been turned into a simple routine in the Bureau of Records of the Milk Marketing Board and several thousand bulls have now been evaluated. In this paper, we shall be mostly concerned to use this material to investigate the heritabilities of milk yield and fat content and the relationship between the two in the different breeds. The information that we shall use consists, for each bull, of the mean contemporary comparison, with its effective ‘weight’, and the average fat percentage of the daughters. Before we deal with the observed results, we should go into rather more detail into the nature of these two figures and into the factors affecting them.



Agronomy ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 103 ◽  
Author(s):  
Rafał Ogórek ◽  
Agnieszka Lejman ◽  
Piotr Sobkowicz

Harrowing is one of the most popular mechanical methods to control weeds. Nevertheless, the relationship between the effect of different harrowing intensities using spike-tooth harrow in barley-pea intercrop on the yield and mycoflora of grains has not yet been studied. Therefore, the aim of this study was to assess the effect of harrow intensity using spike-tooth harrow in barley-pea mixture on the mycological quality of harvested grains, grain yield, as well as influence of barley and pea grain moisture on the abundance of fungi. The field experiment was carried out during 2010–2012, and it was conducted using a randomized complete block design with four replicates. Weed control was mechanical and chemical. In this study, we have shown that harrowing in barley-pea intercrops does not reduce the yield of either mixture components, both with respect to grain quantity or mycological quality after harvest, compared to controls—without harrowing and the herbicide MCPA (2-methyl-4-chlorophenoxyacetic acid). However, increasing the intensity of harrowing did not result in a consistently larger crop yield or reduction in fungal abundance in the grains. The grains’ internal structures and surface of both tested components of the mixture were colonized to a large extent by cosmopolitan fungi, of which Alternaria alternata (Fr.) Keissl. was the most abundant.



2012 ◽  
Vol 549 ◽  
pp. 491-495
Author(s):  
Wan You Zhang ◽  
Xin Yan Wang ◽  
Li Juan Xi

In order to study the relationship between extracellular polymeric substances (EPS) and membrane fouling, the effect of extracellular polymeric substances (EPS) on the operation of membrane bioreactor (MBR) was investigated in this paper. The operation of membrane was analyzed by evaluating sludge volume index (SVI), modified fouling index (MFI), and membrane resistance (Rt), respectively. The results showed that SVI, MFI, and Rt increased with the accumulation of EPS, and membrane fouling aggravated with the increase of EPS, this illustrated that the content of EPS had a direct influence on SVI, MFI, Rt and membrane fouling. The consequences could offer a simple method to monitor the concentration of EPS by analyzing SVI, MFI, or Rt.



2009 ◽  
Vol 131 (3) ◽  
Author(s):  
George G. Adams ◽  
Palaniappan Nagappan ◽  
Nicol E. McGruer

A simple method to determine the frictional interaction between a carbon nanotube (CNT) and a substrate is analyzed for feasibility. In this technique an atomic force microscope (AFM) tip is used to drag a CNT along a substrate. Then the deformed shape of the CNT can be viewed either with the AFM or in a scanning electron microscope. An analysis of the steady-state deformed shape allows the determination of the frictional interactions, which occurred during dragging. It is important to quantify these interactions in a variety of potential applications of nanotechnology. In one such example, a CNT based nanoswitch consists of a CNT bridging over a trench. Actuation of the CNT causes it to stretch and can lead to partial slip at the interface. This slip causes hysteresis, which has been observed in the mechanical actuation of a CNT bridge. In this paper continuum level modeling of the frictional interaction is used to determine the relationship between the steady-state deformed shape of the CNT and the frictional interaction, which occurred between the CNT and substrate during dragging. The model and analysis indicate that this method should be feasible for CNTs with aspect ratios approximately in the 100–250 range.



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