Changes with time of crop yields in a long-term experiment

1988 ◽  
Vol 111 (2) ◽  
pp. 317-332 ◽  
Author(s):  
G. V. Dyke

SummaryYields of the three ‘test’ crops, winter wheat, potatoes, spring barley in the Rothamsted Ley–Arable experiments 1949–69 increased by about 100%, 80%, 40% respectively, each in a period of 19 years. The wheat variety was changed once during the period and this change is enough to explain most of he increase of yield. For potatoes there was no change of variety; the estimated effects of changes in manuring, etc. explain less than one third of the observed increase. For barley two changes of variety explain about one third of the increase; most of the remainder may be explained by improved manuring of preceding crops, especially potatoes. After 1969 the cropping was drastically changed but a few recent yields from other experiments at Rothamsted indicate that the steady rates of increase may have continued at least up to 1980.

1963 ◽  
Vol 61 (2) ◽  
pp. 173-185 ◽  
Author(s):  
M. G. Barker

A long-term experiment designed to study the effects on crop yields of different basic methods of cultivation used in the preparation of seedbeds is described and the results of the first completed cycle of 4 years are discussed. Four basic methods of cultivation were compared, namely, ploughing, rotary cultivating, cultivating and discing. Each one of these was done, early and late, for each crop in two four-course rotations which differed only in the cropping of 1 of the 4 years when potatoes were used in one case and a 1-year ley in the other. Each crop in the rotation (winter wheat, sugar beet, barley, ley or potatoes) was grown at two levels of fertilizer application and provision was made in the design of the experiment for two different weed control régimes. The soil was fairly easy to work, being of the Milton series of river gravels.As a result of the work described, the following conclusions have been drawn:1. Ploughing was the most consistent method of providing a satisfactory basis for the final seedbed preparation but in some circumstances other methods were equally good. On average, ploughing led to the highest yields and discing the lowest, with rotary cultivating second and cultivating third in order of merit.2. The yields of cereals grown after root crops were not dependent on the method of basic cultivation used.3. The effects of the cultivations on the yield of winter wheat after the ley appeared to be due to the extent to which the regrowth of rye-grass was controlled, the plough being most effective in this respect.


2021 ◽  
Vol 264 ◽  
pp. 108083
Author(s):  
J. Macholdt ◽  
S. Hadasch ◽  
H.-P. Piepho ◽  
M. Reckling ◽  
A. Taghizadeh-Toosi ◽  
...  

2013 ◽  
Vol 62 (2) ◽  
pp. 311-330
Author(s):  
Jakab Loch ◽  
János Lazányi

Az Országos Műtrágyázási Tartamkísérletek (OMTK) tizenkét NPK kezeléskombinációjában, kilenc termőhelyen vizsgáltuk az NPK-trágyázás hatását az őszi búza és a kukorica termésére és a talajok 0,01 M CaCl2-oldható tápelemtartalmára. A termőhelyek: Bicsérd (BI), Hajdúböszörmény (HA), Iregszemcse (IR), Karcag (KA), Keszthely (KE), Kompolt (KO), Mosonmagyaróvár (MO), Nagyhörcsök (NA), Putnok (PU). Az NPK kezelések: 000, 101, 111, 121, 201, 220, 221, 222, 331, 341, 421, 441. A N- és P-kezelések a kódoknak megfelelően 50 kg N, ill. P2O5·ha−1, a K-adagok 100 kg K2O·ha−1 hatóanyag-mennyiséggel növekszenek. Az őszi búza termésadatok a 23., 24., 27., 28. és 31. évi kísérletekből, a kukoricatermések a 25., 26., 29. és 30. évből származnak.Az NPK-kezelések jelentősen növelték az őszi búza és a kukorica öt-, illetve négyéves átlagtermését, szignifikáns különbségek jöttek létre a termőhelyek átlagában. Az NPK-kezelések különböző érvényesülése az egyes termőhelyeken az eltérő ökológiai viszonyok, köztük a különböző eredeti tápelemtartalom és szolgáltató képesség következménye.Az NPK-kezelések hatására a talajok 0,01 M CaCl2-oldható tápelemtartalma is jelentősen változott. A növények tápelemigényét meghaladó kezelések tartamhatásaként tápelem-felhalmozódás igazolható mindhárom tápelem esetében. A növények szükségletét meghaladó N-adagok, a karbonátos talajokat és a nagy agyagtartalmú kompolti (KO) talajt kivéve csökkentették a talaj pH-t. A másodfokú görbék az őszi búza ötéves termésátlaga és a 0,01 M CaCl2-ban mért összes-N, P- és K-tartalom közötti összefüggéseket szemléltetik termőhelyenként.A legnagyobb kezeléshatások azokon a talajokon igazolhatók, melyeken a kontroll 0,01 M CaCl2-oldható összes-N értéke kisebb, mint 5–10 mg·kg−1. A 15,0 mg·kg−1 érték felett altalaban nem érvényesült a nitrogén termésnövelő hatása. Kivételt képez a tápanyagban gazdag, hajdúböszörményi nem karbonátos réti talaj. A foszfor termésnövelő hatása 2,0 mg P·kg−1 érték felett — a karbonátos réti talaj kivételével — általában nem érvényesül. Az összefüggéseket jellemző R2 meghatározottsági tényezők a legkisebbek az őszi búza és a talaj 0,01 M CaCl2-oldható K-tartalma között, ami az egyéb tényezők nagyobb szerepére utal.A bemutatott eredmények igazolják, hogy a 0,01 M CaCl2-oldható N-, P- és Kfrakciók alkalmasak a tápanyaghiány és -felesleg jellemzésére. Egyben igazolják, hogy az eltérő ökológiai viszonyok között nagyobb terméskülönbségek jöhetnek létre, mint a kezelések hatására. A környezetkímélő tápanyag-gazdálkodás megköveteli a tápanyagok eltérő érvényesülésének figyelembevételét.A termésadatok átengedéséért köszönet az OMTK Hálózati Tanács elnökének, titkárának, és valamennyi kísérletfelelősnek.


Agronomy ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 34 ◽  
Author(s):  
Huasen Xu ◽  
Huaxing Bi ◽  
Lubo Gao ◽  
Lei Yun

Alley cropping allows the famer to effectively use available resources and yield more benefits. Choosing suitable associated crop and mitigating the competition between trees and crops are crucial for designing the alley cropping systems. We conducted a long-term experiment, including apple (Malus pumila)/peanut (Arachis hypogaea), apple/millet (Setaria italica) and apple/maize (Zea mays) alley cropping systems with conventional intercropping distance, and corresponding monocultures (Exp.1), and a short-term experiment with improved intercropping distance in the same three combinations (Exp.2) in the Loess Plateau, China. The results showed crop yields in three alley cropping systems were lower than the corresponding monocultures. Apple yields were significantly constrained by millet and maize in the alley cropping systems, but not sensitive to the presence of peanut. Land equivalent ratios (LERs) ranged from 0.44 to 0.89 before the tree bore fruit. The LERs were greater than 1.0 after the tree bore fruit, and the apple trees made a decisive contribution to the land use advantage. Net present values of three alley cropping systems were on average 60.1% higher than the corresponding monocultures across the alley cropping period. The maximum annual present value in the first–fifth, sixth and seventh–ninth years after the alley cropping establishment was observed in the apple/maize, apple/millet and apple/peanut system, respectively. These results highlight that choosing the optimal alley cropping management and suitable associated crops at different years after establishment may allow farmers to increase the land use efficiency and economic profitability.


Pedosphere ◽  
2013 ◽  
Vol 23 (6) ◽  
pp. 835-843 ◽  
Author(s):  
Wei ZHOU ◽  
Chun-Sheng HU ◽  
Ji LI ◽  
P. CHRISTIE ◽  
Xin-Hua HE ◽  
...  

2016 ◽  
pp. 9-13
Author(s):  
Gergely Szilágyi

We tested the fertilizer reaction of four different winter wheat varieties in three different crop years, on chernozem soil, in long-term experiment. We examined the optimum fertilizer requirements and the maximum yield of the varieties. According to our results there were significant differences among the years: the yield of the winter wheat varieties changed between 1.4–6.1 t ha-1 in 2013, 3.8–8.6 t ha-1 in 2014 and 3.2–8.6 t ha-1 in 2015. The yield increasing effect of fertilization was significantly different in the tested years. The optimum level of fertilization was determined by, besides the genetic differences among the varieties, the crop year and the extent of fertilization. In milder winter months, due to the higher average temperatures, yields of winter wheat increased compared to an average crop year.


Author(s):  
J. E. Holland ◽  
P. J. White ◽  
J. -N. Thauvin ◽  
L. Jordan-Meille ◽  
S. M. Haefele ◽  
...  

AbstractLiming has widespread and significant impacts on soil processes and crop responses. The aim of this study was to describe the relationships between exchangeable cation concentrations in soil and the relative yield of spring barley. The hypothesis was that yield is restricted by the concentration of a single exchangeable cation in the soil. For simplicity, we focused on spring barley which was grown in nine years of a long-term experiment at two sites (Rothamsted and Woburn). Four liming rates were applied and in each year the relative yield (RY) and the concentrations of exchangeable cations were assessed. Liming had highly significant effects on the concentrations of most exchangeable cations, except for Cu and K. There were significant negative relationships (either linear or exponential) between the exchangeable concentrations of Mn, Cd, Cr, Al, Fe, Cu, Co, Zn and Ni in soil and soil pH. The relationships between RY and the concentrations of selected exchangeable cations (Mn, Ca and Al) were described well using log-logistic relationships. For these cations a significant site effect was probably due to fundamental differences in soil properties. At both sites the concentrations of exchangeable soil Al were excessive (> 7.5 mg kg−1) and were most likely responsible for reduced barley yields (where RY ≤ 0.5) with soil acidification. At Rothamsted barley yield was non-limited (where RY ≥ 1) at soil exchangeable Mn concentrations (up to 417 mg kg−1) greater than previously considered toxic, which requires further evaluation of critical Mn concentrations.


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