EFFECT OF ROTATIONS, TILLAGE TREATMENTS AND FERTILIZERS ON THE AGGREGATION OF A CLAY SOIL

1971 ◽  
Vol 51 (2) ◽  
pp. 235-241 ◽  
Author(s):  
G. S. EMMOND

Soil aggregation was lowest in a fallow-wheat rotation and increased in other fallow-grain rotations with the second, third, and fourth crops after the fallow year. The best aggregation was under continuous wheat. Rotations containing hay crops, particularly those with grass, increased soil aggregation significantly. The influence of tillage treatments on soil aggregation declined with increased depth. Various tillage treatments affected surface soil aggregation, in the following order: green manure crop plowed under > cultivated with trash cover > crop residues plowed under > cultivated with residues burned off = crop residues disced in. Fertilizer (11–48–0) applied to the wheat crop of the various tillage treatments increased soil aggregation except where the crop residues had been removed. The application of barn manure increased soil aggregation.

2021 ◽  
Author(s):  
Sandeep Sharma ◽  
Sukhjinder Kaur ◽  
Om Parkash Choudhary

Abstract The sustainability of rice-wheat system (RWS) in north-western India is threatened due to the deterioration of soil health and emergence of new challenges of climate change caused by low nutrient use efficiency and large scale burning of crop residues. Phosphorus and phosphatase activities in the soil aggregates affected by different residue management practices remain poorly understood. Thus, soil samples were obtained after a five year field experiment to identify the effect of tillage, green manure and residue management on aggregate-associated phosphorus fractions. In rice, the main plot treatments were combinations of wheat straw and Sesbania green manure (GM) management: (1) puddled transplanted rice (PTR) with no wheat straw (PTRW0), (2) PTR with 25% wheat stubbles (12-15 cm long) retained (PTRW25), (3) PTR without wheat straw and GM (PTRW0+GM), and (4) PTR with wheat stubbles (25%) and GM (PTRW25+GM). Three sub-plots treatments in the successive wheat crop were (1) conventional tillage with rice straw removed (CTWR0), (2) zero tillage (ZT) with rice straw removed (ZTWR0) and (3) ZT with 100% rice straw retained as surface mulch (ZTWR100). Results of the present study revealed that all phosphorus fractions were significantly higher in PTRW25+GM followed by ZTWR100 compared with PTRW0/CTWR0 treatment within both macro- and micro-aggregates. The total phosphorus (P), available P, alkaline phosphatase and phytin-P were significantly higher under ZTWR100 than CTWR0. Principal component analysis identified NaOH-Po, NaHCO3-Pi and HCl-P as the dominant and reliable indicators for evaluating P transformation within aggregates under conservation agriculture based practices.


1999 ◽  
Vol 79 (1) ◽  
pp. 11-17 ◽  
Author(s):  
S. A. Brandt

Previous research with lentil (Lens culinaris Medic.) green manure in the semiarid prairies of western Canada has indicated that water use by the green manure crop often reduces grain yield of the succeeding cereal crop compared to those obtained after conventional summerfallow. In this study, we evaluated several green manure management practices that have potential to trap snow and enhance overwinter soil water recharge. These practices included: using herbicides to halt the growth of the green manure crop thus eliminating the need for soil incorporation, planting mustard (Sinapis alba L.) strips after incorporation, and leaving standing strips of non-incorporated lentil. Our results showed that none of the green manure management strategies increased wheat (Triticum aestivum L.) yield or grain protein concentration compared to wheat grown on conventional summerfallow. Leaving strips of standing lentil during bud stage incorporation provided barriers for wind erosion protection, while not decreasing wheat yield or protein content. Glyphosate or 2,4-D amine applied at bud stage of the lentil, and without soil incorporation, reduced available soil N. However, 2,4-D did not halt plant growth and water use quickly enough to avoid reducing yield of the succeeding wheat crop, while glyphosate generally halted water use more rapidly. The inability of the green manure management strategies to increase wheat yields over that obtained from conventional summerfallow was because the soil rooting zone is typically filled to capacity with water by this latter practice under the prevailing soil and climatic conditions. If green manuring is practised, early incorporation with lentil leave strips is the most promising management system. However, even with improved water management practices, green manuring did not demonstrate a consistent advantage over summerfallow, which may be required to offset the added economic costs required to enact this practice. Key words: Lens culinaris, legumes, summerfallow, soil nitrogen, soil water, wheat


1990 ◽  
Vol 30 (5) ◽  
pp. 645 ◽  
Author(s):  
JH Silsbury

Pea (Pisum sativum L. cv. Alma), vetch (Vicia sativa L. cv. Languedoc) and annual medic (Medicago truncatula Gaertn. cv. Paraggio) were grown at Brinkworth, South Australia, in 1987 in large (0.75 ha) plots and subjected to 3 systems of management: (i) ploughing in at flowering as a green manure crop, (ii) harvesting for grain and ploughing in the dry residues, and (iii) harvesting for grain and removing the residues. A wheat crop was sown over the whole area in the following season (1988) and the effects of type of legume and management on grain yield and grain protein content were measured. The management system imposed on the legume had a highly significant (P<0.01) effect on the grain yield of the following wheat crop, but there were no significant differences between the 3 legumes in their effects on wheat yield or on grain protein content. Ploughing in the legumes as a green manure crop at flowering added about 100 kg/ha more nitrogen (N) to the soil than allowing the legumes to mature, harvesting for seed, and removing residues. Incorporating the dry residues rather than removing them added about 26 kg N/ha. The green manure crop significantly increased subsequent wheat yield (by 49%; P<0.001) and protein content of the grain (by 13%; P<0.05) compared with the treatment in which the legumes were harvested for grain and all residues removed; incorporating the dry residues increased yield by 10%. It is concluded that the amount of N added during the legume phase in a rotation is more important than the kind of legume from which the N is derived. The occasional use of a dense legume crop as a green manure may rapidly add a large amount of N to a soil to be slowly exploited by following grain crops.


2012 ◽  
Vol 27 (1) ◽  
pp. 60-67 ◽  
Author(s):  
Steven J. Shirtliffe ◽  
Eric N. Johnson

AbstractOrganic farmers in western Canada rely on tillage to control weeds and incorporate crop residues that could plug mechanical weed-control implements. However, tillage significantly increases the risk of soil erosion. For farmers seeking to reduce or eliminate tillage, potential alternatives include mowing or using a roller crimper for terminating green manure crops (cover crops) or using a minimum tillage (min-till) rotary hoe for mechanically controlling weeds. Although many researchers have studied organic crop production in western Canada, few have studied no-till organic production practices. Two studies were recently conducted in Saskatchewan to determine the efficacy of the following alternatives to tillage: mowing and roller crimping for weed control, and min-till rotary hoeing weed control in field pea (Pisum sativum L.). The first study compared mowing and roller crimping with tillage when terminating faba bean (Vicia faba L.) and field pea green manure crops. Early termination of annual green manure crops with roller crimping or mowing resulted in less weed regrowth compared with tillage. When compared with faba bean, field pea produced greater crop biomass, suppressed weeds better and had less regrowth. Wheat yields following pea were not affected by the method of termination. Thus, this first study indicated that roller crimping and mowing are viable alternatives to tillage to terminate field pea green manure crops. The second study evaluated the tolerance and efficacy of a min-till rotary harrow in no-till field pea production. The min-till rotary hoe was able to operate in no-till cereal residues and multiple passes did not affect the level of residue cover. Field pea exhibited excellent tolerance to the min-till rotary hoe. Good weed control occurred with multiple rotary hoe passes, and pea seed yield was 87% of the yield obtained in the herbicide-treated check. Therefore, this second study demonstrated that min-till rotary hoeing effectively controls many small seeded annual weeds in the presence of crop residue and thus can reduce the need for tillage in organic-cropping systems.


2012 ◽  
Vol 29 (1) ◽  
pp. 42-47 ◽  
Author(s):  
Drew J. Lyon ◽  
Gary W. Hergert

AbstractOrganic farming systems use green and animal manures to supply nitrogen (N) to their fields for crop production. The objective of this study was to evaluate the effect of green manure and composted cattle manure on the subsequent winter wheat (Triticum aestivumL.) crop in a semiarid environment. Dry pea (Pisum sativumL.) was seeded in early April and terminated at first flower in late June. Composted cattle manure was applied at 0, 11.2 or 22.5 Mg ha−1just prior to pea termination. Winter wheat was planted in mid September following the green manure or tilled summer fallow. No positive wheat response to green manure or composted cattle manure was observed in any of the 3 years of the study. In 2 of the 3 years, wheat yields and grain test weight were reduced following green manure. Green manure reduced grain yields compared with summer fallow by 220 and 1190 kg ha−1in 2009 and 2010, respectively. This may partially be explained by 40 and 47 mm less soil water at wheat planting following peas compared with tilled summer fallow in 2008 and 2009, respectively. Also, in 2008 and 2009, soil nitrate level averaged 45 kg ha−1higher for black fallow compared with green manure fallow when no compost was added. Organic growers in the semiarid Central Great Plains will be challenged to supply N fertility to their winter wheat crop in a rapid and consistent manner as a result of the inherently variable precipitation. Growers may need to allow several years to pass before seeing the benefits of fertility practices in their winter wheat cropping systems.


2010 ◽  
Vol 2 (1) ◽  
Author(s):  
CS Wortmann ◽  
M Isabirye ◽  
S Musa

2021 ◽  
Author(s):  
Usha Nandhini Devi Harinarayanan ◽  
Pugalendhi Lakshmanan

Present day agricultural practices are posing a serious threat to the human population due to unscrupulous use of chemical fertilizers and pesticides. Conventional agricultural practices wherein large quantities and unscrupulous use of chemical fertilizers and pesticides are no longer safer as it directly enter the food chain. Hence, organic cultivation of vegetables is gaining momentum among the growing population. Organic practices rely on crop rotations, crop residues, plant and animal manures, growing of legume and green manure crops and biological control of pests and diseases. It aims to combine tradition, innovation and science in a balanced proportion to utilize the environment in safer manner and maintain ecological balance. Organic cultivation assures protection of the environment and plays a major role on the economy of a nation. Sustainable production of organic vegetables needs to be ensured to fetch premium price in the domestic as well as international markets. Organic farming has shown expansion in the recent years in the European countries offering scope for a better price in the international market.


2013 ◽  
Vol 33 (5) ◽  
pp. 965-975 ◽  
Author(s):  
Aloisio Bianchini ◽  
Pedro H. de M. Borges

The destruction of the cotton crop residues (cotton stalks) is a mandatory procedure in Brazil for prophylactic issues, but is a subject unexplored by the research and there are few studies that deal with this issue. However, this is not encouraged in recent decades, studies aimed at developing and evaluating equipment for this purpose. The present study had the objective to evaluate six methods for mechanical destruction of cotton crop residues. Each method was defined based on the principle of operation of the active parts of the equipment, which were tested in medium texture soil and in a clayey one. The variables used to evaluate the efficiency of the equipment were the regrowth rate, the theoretical field capacity and energy demand. The equipment with convergent concave disks (DCC) and flat cutters discs from manufacturer A (CPS-a) showed the best results in cotton stalks destruction in both soil types. The harrow disc (GPD) was efficient only in clay soil. It was concluded that the equipment with convergent concave disks, among those tested, was the most efficient to destroy cotton stalks, regardless of soil type, and that the harrow disc was not included among the best performers.


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