ARTICLE INFORMATION	ABSTRACT
Article history:  Received: 31.07.2021 Accepted: 10.08.2021 Published: 31.10.2021  *Corresponding author: Ágnes Hadhazy  E-mail:   madawy78@mans.edu.eg   Keywords:  Rye  Fallow  Straw manure  Farmyard manure  Green manure	Research work was carried out in Westsik’s crop rotation long-term field experiment during the 2018 and 2019 seasons. The Westsik’s crop rotation long-term field experiment includes fifteen crop rotations (CR), but this study focused on only seven crop rotations  (CRs) i.e. (I, VI, VII, X, XI, XIV, and XV). The main purpose of this study was to analyze the effects of long-term crop rotations on rye spike components. Results showed that the effect of the applied straw manure and lupine green manure without chemical fertilizer resulted in the lowest results at every analyzed spike parameter in both years. The fallow was able to result in better spike parameters than the straw manure or lupine green manure without chemical fertilizer. The farmyard manure without chemical fertilizer was more effective than straw manure or lupine green manure without chemical fertilizer at all analyzed spike parameters. The results of correlation analysis indicated a close, positive correlation between the seed weight/spike and spike length, spike weight, and the 1000  seed weight. While the correlation was medium and positive between the seed weight/spike and spike weight in the 2018 season.  Moreover, the correlation was close and positive between the seed weight/spike and all other analyzed spike parameters in the 2019  season.

INTRODUCTION  

Winter rye (Secale cereale L.) is an important cereal crop well adaptive for growing in newly reclaimed sandy soil, its seed is used for both human consumption and animal feeding (Bushuk, 2001). According to (FAO,  2020) the total production area of rye in  Hungary reached about 25767 hectares with a total production of 84.116 tonnes. 

The fallow system was not a modern soil cultivation method when our research field experiment was established in 1929 but it has many benefits for the soil. Vilmos  Westsik wanted to compare its effect with different organic and chemical fertilization effects. In this connection, applying the land fallow is a natural soil fertility regeneration method (Barrios et al., 2005).

The farmers let the land fallow for the restoration of soil fertility in the tropical area (Sánchez, 1995). Fallow is used for sustainable soil fertility improvement (Tian et al., 2005). In general,  using different manuring methods in a long-term field experiment is well known worldwide having a lot of advantages.

Many researchers noticed that long-term organic manure application improves the soil’s physical and chemical properties, increases the carbon concentration in the soil, and consequently increases the soil fertility  (Kätterer et al., 2011).

Applying organic manure significantly increased the organic carbon content of the soil and soil fertility which is realized in yield parameters as compared to chemical fertilizer (Dersch and  Bohm, 2001). In addition, using organic manures in combination with inorganic fertilizers increase the nitrogen (N) and phosphorus (P) contents of soil, maintains and renews the organic matter of soil, and improves the physical and chemical properties of soil (Alam et al., 1997).

Organic manure has several benefits, like balancing the nutrient supply including the micronutrients, increasing the soil nutrient availability, increasing the soil microbial activity, improving the soil structure, and increasing soil water availability (Han et al.,  2016). 

Many researchers found that rye seed components i.e. spike parameters are strongly influenced by not only the soil fertility but the manuring system, too. Also,  spike length, spike weight, and seed weight/spike determine the yield of rye and they have a  positive connection with rye yield (Kilic and  Yaǧbasanlar, 2010). Moreover, seed weight/spike is considered the most important component of grain yield  (Yaǧbasanlar and Ozkan, 1995; Parado and  Joshi, 1970). 

Thus, the purpose of this study was to analyze the effect of organic manuring methods of Westsik’s crop rotation long-term field experiment on spike parameters of winter rye plants. 

MATERIAL AND METHODS 

Study site and objectives 

Research work was carried out during 2018  and 2019 at the Westsik’s crop rotation long-term field experiment, Research Institute of  Nyíregyháza, IAREF, University of Debrecen,  Hungary. The winter rye was sown in September 2017 and October 2018 in both seasons, respectively. The soil of this experiment is acidic sandy soil (pHKCL 3.80- 5.17) with low humus content (0.43-0.86%)  in the 0-20 cm soil layer.  

The Westsik’s crop rotation long-term field experiment includes fifteen crop rotations  (CR), but this study focused on only seven crop rotations (CRs) i.e. (I, VI, VII, X, XI, XIV,  XV) as presented in Table 1. In gernal, the 

fallow was applied before the rye plant (CR I);  straw manure was applied directly before the rye plant in CRs VI and VII; farmyard manure was applied to the rye plant in CRs X and XI  and the lupine green manure (as a second crop) was grown as a previous crop before sowing rye plant in CRs XIV and XV.  

Sampling and measured parameters

Rye plant samples were collected at the end of ripening, on the 2^nd and 11^th of July in both seasons, respectively. The plant samples were harvested by using a square wooden frame 100 × 100 cm (1m-2), three repetitions/plot. The spike parameters i.e., spike length (cm), spike weight (g), and seed weight/spike (g) were determined from 10  spikes per m-2. To determine the 1000-grain weight (g), 1000 grains from each sample were measured. The ratio of seed weight/spike to the weight of spike was calculated. 

Table 1. The number of crop rotations, the applied fertilization methods, and fertilization doses of the rye before its sowing in Westsik’s crop rotation experiment. Numbers  indicate the applied fertilizers/manures of the studied rotation phase 

Number of crop  rotation	N (kg ha-1 active  ingredient)	P2O5 (kg ha 1 active  ingredient)	K2O (kg ha-1 active  ingredient)	Farmyard  manure (t ha-1)	Straw  manure (t ha-1)	Lupine green  manure as a  second crop
I						–
VI	65	47	56		26.1	–
VII					26.1	–
X				26.1		–
XI		31	28	26.1		–
XIV	43	31	28			+
XV						+

Statistical analysis 

The obtained data were statistically analyzed using the IBM SPSS Statistical Software  Package 21.0 version by one-way ANOVA as described by (Snedecor and Cochran, 1980)  then Tukey’s test, P<0.05 as mentioned (Tukey, 1977) was used to compare the means. In addition, Pearson’s correlation analysis was done to find relations between the fertilization methods and rye yield components. 

RESULTS  

Spike length 

Data presented in Table 2 clearly show that the average rye spike length in the crop rotations was between 4.3 and 8.1 cm in  2018 and between 6.4 and 9.4 cm in 2019.  The CR I resulted in a 7.6 cm spike length in  2018, and 6.7 cm in 2019. The straw manured with chemical fertilizer resulted in longer spikes (8.1 and 8.6 cm) than CR VII without chemical fertilizer (4.3 and 6.4 cm) in both years, respectively. Moreover, using the  

farmyard manure with chemical fertilizers resulted in the highest averages of spike length (7.6 cm) in 2018, while a longer spike  (9.4 cm) resulted in CR X of farmyard manure without chemical fertilizer in 2019. Also, at lupine green manured CRs XIV and XV, where lupine was grown as a second crop, CR XIV  resulted in longer spikes with chemical fertilizer (6.6 and 9.0 cm) than CR XV without fertilizer (5.9 and 7.1 cm) in both years,  respectively. Straw manure and lupine green manure with NPK fertilizer resulted in longer spikes compared to similar CRs without  NPK fertilizer.

On the other hand, results of statistical analysis in the 2018 and 2019  seasons, showed that CR VII without chemical fertilizers produced the shortest spikes (4.3 and 6.4 cm), respectively. The straw manure with chemical fertilizer was more effective than farmyard manure or lupine green manure (as a second crop). The farmyard manure was more effective in the  2018 season as compared with the 2019  season. 

Table 2. Spike length (cm) as influenced by Westsik’s crop rotation experiment (mean ±  standard deviation, n=3).

Crop rotations system	2018	2019
I	7.6 ± 0.93 c	6.7 ± 0.34 a
VI	8.1 ± 0.61 c	8.8 ± 0.41 b
VII	4.3 ± 0.10 a	6.4 ± 0.85 a
X	6.8 ± 0.20 bc	9.4 ± 0.78 b

XI	7.6 ± 0.26 c	8.9 ± 0.35 b
XIV	6.6 ± 0.51 bc	9.0 ± 0.40 b
XV	5.9 ± 0.96 b	7.1 ± 0.58 a
Main average	6.7 ± 1.33	8.0 ± 1.29

Different letters indicate significant differences of means according to Tukey’s test (p<0.05). 

Spike weight 

Data presented in Table 3 clearly show that the different fertilization methods resulted in different spike weights. The main averages of spike weight were 1.000 and 1.171 g in 2018  and 2019, respectively. The CR I produced  1.267 and 0.907 g of spike weight in 2018 and  2019, resp.

In addition, applying straw manure besides using chemical fertilizers in  CR VI resulted in the highest values of spike weight (1.500g and 1.263g) as compared with without chemical fertilizer in CR VII  (0.433 and 0.673g) in both seasons,  respectively. Also, applying farmyard manured in CR X and XI resulted in spike weights of 1.067 and 1.267g and 1.570 and 1.446  g in both seasons, respectively.

The rye plants received farmyard manure with or without chemical fertilizers resulted in the highest values of spike weight in 2019. Moreover, the lupine green manure with chemical fertilizer in CR XIV resulted in a higher spike weight  (0.900 and 1.421g) as compared with without chemical fertilizers in CRXV (0.700 and  0.919g).

On the other side, straw-manured CR VII resulted in the lowest averages of spike weight (0.433 and 0.673g) in both years, respectively. The farmyard manure besides chemical fertilizers and fallow system resulted in the same effect as the increase of spike weight this year moreover, the results of statistical analysis showed a significant difference between the manuring systems in both years as shown in Table 3. 

Seed weight/spike 

Data presented in Table 4 clearly show that the crop rotation system significantly affected seed weight/spike in both years.  Results show that the highest values of seed weight/spike were resulted from CRs VI, XI, 

and I and without significant differences between them. The corresponding data were  1.233, 1.067, and 1.033 in the first year,  respectively. On the other side, straw manured without chemical fertilizer CR VII  recorded the lowest values of seed weight/spike (0.333) in the first year. Lupine green manure with chemical fertilizer CR XIV  produced a higher seed weight/spike  (0.700g) than without chemical fertilizer CR  XV (0.500g).  

Table 3. Spike weight (g) as influenced by Westsik’s crop rotation experiment (mean±  standard deviation, n=3) 

Crop rotations system	2018	2019
I	1.267 ± 0.57 de	0.907 ± 0.12 ab
VI	1.500 ± 0.20 e	1.263 ± 0.19 bc
VII	0.433 ± 0.57 a	0.673 ± 0.16 a
X	1.067 ± 0.57 cd	1.570 ± 0.07 c
XI	1.267 ± 0.57 de	1.446 ± 0.09 c
XIV	0.900 ± 0.10 bc	1.421 ± 0.13 c
XV	0.700 ± 0.17 b	0.919 ± 0.21 ab
Main average	1.000 ± 0.36	1.171 ± 0.31

Different letters indicate significant differences of means according to Tukey’s test (p<0.05).

---

 As shown in Table 4 there are no significant differences between the CRs X, XI, XIV, and VI  on seed weight/spike during the second year of 2019, these CR achieved the highest values of these characters (1.317, 1.199, 1.165, and  1.029g, respectively). Moreover, straw manure plus chemical fertilizer produced a  higher seed weight/spike in CR VI (1.029g)  than without chemical fertilizers in CR VII (0.501g).

Also, the farmyard manure is not significant. Regarding the lupine green manure gave a higher seed weight/spike with chemical fertilizer gave a higher seed weight/spike in CR X (1.317g) than with chemical fertilizer in CR XI (1.199g) but the difference between these data was not chemical fertilizer in CR XIV (1.165g) than without chemical fertilizer in CR XV (0.733g).  

Table 4. Seed weight/spike (g) as influenced by Westsik’s crop rotations experiment (mean±  standard deviation, n=3) 

Crop rotations system	2018	2019
I	1.033 ± 0.57 de	0.737 ± 0.12 ab
VI	1.233 ± 0.15 e	1.029 ± 0.19 bc
VII	0.333 ± 0.05 a	0.501 ± 0.16 a
X	0.867 ± 0.05 cd	1.317 ± 0.07 c
XI	1.067 ± 0.05 de	1.199 ± 0.09 c
XIV	0.700 ± 0.10 bc	1.165 ± 0.13 c
XV	0.500 ± 0.10 ab	0.733 ± 0.21 ab

Main average 0.800 ± 0.31 0.954 ± 0.31 Different letters indicate significant differences of means according to Tukey’s test (p<0.05). 

---

According to the results of the statistical analysis presented in Table 4, the seed weight/spike in CRs VII and XV were significantly different from the CRs I, VI, X., and XI data in the 2018  season. Moreover, seed weight/spike in CRs  I, VII, and XV were significantly different from  CRs X, XI, and XIV data in the 2019 season.  Also, CRs I, VII, and XV produced the lowest values of seed weight/spike. In these  CRs, only straw manure (VII), lupine green manure as a second crop (XV), and fallow (I)  were applied without chemical fertilizers. 

1000 seed weight 

1000 seed weight (g) was significantly affected by the crop rotations system in both years. Results in Table 5 showed that the main averages of 1000 seed weights were  24.400 and 26.881g in both years. Farmyard manure plus phosphorous and potassium chemical fertilizers in CR XI resulted in the highest values of 1000 seed weight (27.700g)  in the first year.

The CRs VI, I, and XIV  recorded the second rank without significant differences between them. The corresponding data were 25.933, 24.967, and  24.733g in 2018, respectively. On the other hand, CRs VII and XV recorded the lowest averages of 1000 seed weights (21.500 and  21.667g) in 2018. 

Table 5. 1000seed weight (g) as influenced by Westsik’s crop rotations experiment (mean±  standard deviation, n=3) 

Crop rotations system	2018	2019
I	24.967 ± 0.86 bc	27.000 ± 1.80 bc
VI	25.933 ± 0.73 c	26.500 ± 0.87 bc
VII	21.500 ± 0.26 a	22.500 ± 0.50 a
X	24.233 ± 0.28 b	29.667 ± 1.61 c
XI	27.700 ± 0.70 d	28.333 ± 2.57 bc
XIV	24.733 ± 0.80 bc	29.000 ± 0.87 bc
XV	21.667 ± 0.23 a	25.167 ± 1.15 ab
Main average	24.400 ± 2.16	26.881 ± 2.69

Different letters indicate significant differences in means according to Tukey’s test (p<0.05). 

Correlation analysis

Regarding the obtained results in Table 5,  1000 seed weight was higher in CRs X, XIV, I, and VI, and there were no significant differences between them in 2019, a weight of 28.333g in 2019. It could be noticed that using farmyard manure in a long-term period, plus or without NPK fertilizer led to increasing the soil cation exchange capacity and the organic carbon content of the soil.  Lupine green manure without chemical fertilizer in CR XV resulted in 25.167g for  1000 seed weight in the 2019 year. 

Data statistical analysis showed that CRs VII  and XV were significantly different from all of the other data recorded from other crop rotation systems. As shown in Table 5, these crop rotations recorded the lowest values of  1000 seed weight (21.500 and 21.667g) in the 2018 seasons. Also, CR VII recorded 22.500g  and was significantly different from CRI, VI, X,  XI, and XIV in 2019. The CR VII received straw manure only.

According to (Prasad 1996)  neither inorganic fertilizer nor organic manure can alone maintain plant productivity. In addition, organic fertilizer  (straw manure and lupine green manure)  with chemical fertilizer, resulted in a higher  1000 seed weight than without chemical fertilizer in both years. corresponding data were 29.667, 29.000,  27.000, and 26.500g, respectively. Also,  applying the farmyard manure with chemical  fertilizer in CR XI resulted in a 1000-seed  

The ratio of seed weight/spike to spike  weight 

Data presented in Table 6 clearly showed that the ratio of seed weight/spike to spike weight was significantly affected by the crop rotation system in both years. Data revealed that the main averages of this character were  79.44 and 81.06% in both 2018 and  2019years. The straw manure and green lupine manure crop rotations with chemical fertilizer in CRs VI and XIV resulted in a higher ratio of seed weight/spike to spike weight  (82.32%, 81.31%, and 77.59%, 79.48%) than without chemical fertilizer (76.67%, 74.37%  and72.50%, 79.48%) in both years.

In addition, the analyzed data of farmyard manure CRs X and XI was higher with chemical fertilizer (84.19%), than without chemical fertilizer (81.21%) in 2018. While in  2019 the farmyard manure produced a  higher ratio between seed weight/spike and spike weight without chemical fertilizer in CR  X (83.90%), than with chemical fertilizer in CR  XI (82.88%) and the difference between them was not significant. 

Table 6. The ratio of seed weight/spike to spike weight (%) is influenced by Westsik’s crop  rotation experiment (mean ± standard deviation, n=3) 

Crop rotations system	2018	2019
I	81.62 ab± 4.12	81.06 b± 1.83
VI	82.32 ab± 2.31	81.31 b± 1.90
VII	76.67 ab± 2.89	74.37 a± 2.17
X	81.21 ab± 1.05	83.90 b± 0.34
XI	84.19 b± 0.74	82.88 b± 1.36
XIV	77.59 ab± 2.51	81.85 b± 2.10
XV	72.50 a± 9.01	79.48 b± 2.42
Main average	79.44 ± 5.17	80.69 ± 3.34

Different letters indicate significant differences of means according to Tukey’s test (p<0.05). 

Correlation analysis 

Correlation coefficients indicated a positive significant correlation between the seed weight/spike and other measured rye yield parameters (Table 7) in both analysed years.  

Data indicated that there was a pronounced positive and close correlation between the seed weight/spike and spike length  (0.913**), spike weight (0.992**), and 1000  seed weight (0.832**). This means, in that crop rotations, which resulted in higher spike long, spike weight, and 1000 seed weight the seed weight was higher.  Moreover, there was a positive and medium correlation between the seed weight and the ratio between seed weight/spike to spike weight in the 2018 season. Several investigations indicated that the grain yield is closely correlated with the number of grains per spike and the number of spikelets  (Perry and D’Antuono, 1989; Sayre et al.,  1997). 

The correlation analysis resulted in a close and positive correlation between all of the analyzed data in 2019 i.e. between the seed weight/spike and spike length (0.938**),  spike weight (0.998**), 1000 seed weight  (0.778**) and the ratio of seed weight/spike to spike weight (0.852**). Moreover, the analyzed data detected between the seed yield and spike weight, seed weight/spike, and number of spikes per area were in positive correlation, as was found by (Nouraein  2019). 

Table7. The correlation coefficient of the linear relationship (R-values) among the  seed weight/spike and other rye spike parameters (n=3) 

Person’s correlation	Spike length  (cm)	Spike  weight (g)	1000 seed  weight (g)	The ratio between  seed weight/spike to  spike weight (%)
Spike weight (g)in  2018 season	0.913**	0.992**	0.832**	0.632**
Spike weight (g) in  2019 season	0.938**	0.998**	0.778**	0.852**

Pearson’s correlation ** Correlation is significant at the 0.01 level.  *Correlation is significant at the 0.05 level.  

DISCUSSION 

According to our results, all spike parameters  (spike length, spike weight, seed weight/spike, 1000 grain weight, and the ratio of seed weight/spike to the weight of spike significantly different from all other crop rotations. Straw manure and lupine green manure with NPK fertilizer resulted in a longer spike compared to similar CRs without NPK fertilizer.

Applying farmyard manure or green manure improved the organic carbon content of the soil which contributes to reaching the higher yield components (Nambiar, 1994; Swarup, 1999;  Kundu et al., 2002; Zhichen et al., 2008),  increasing the soil cation exchange capacity and the organic carbon content of soil and increases the soil microbial activity (Tejada et al., 2008). In addition, applying farmyard manure increased the available nutrient and micronutrient content of soil compared to chemical fertilizers (Hemalatha and Chellamuthu, 2013), increases the available nitrogen content and microorganism activity in the soil, which has a good effect on the next plant production (Bhardwaj et al., 1998). 

In addition, applying organic manure with or without fertilizer to the soil has good benefits for improving the physical and chemical properties of the soil, increasing the spike weight of rye plants (Rabindra et al., 1990; Liu et al., 2010). Using farmyard manure in a long-term period, plus or without NPK fertilizer led to an increase in the soil cation exchange capacity and the organic carbon content of the soil. In addition, applying farmyard manure increased the available nutrient and micronutrient content of soil compared to chemical fertilizers (Hemalatha and  Chellamuthu, 2013).

Applying N fertilizer alone over the years, decreased the number of microbial organisms, enzyme activity, and soil pH, which had a negative effect on the plant yield attributes (Prasad, 1996;  Bandyopadhyay et al., 2010; Liu et al., 2010).  In general, using in combined organic manure and inorganic fertilizer together increases the available NPK content and organic matter content of soil (Gill and Meelu, 1982)  and increases the fertilizer use efficiency and the yield components (Kumar and Mishra,  1992).

These results are similar to those obtained by (Bokhtiar and Sakurai 2006).  Also, at lupine green manured CRs XIV and  XV, where lupine was grown as a second crop, CR XIV resulted in longer spikes with chemical fertilizer than CR XV without fertilizer in both years. In this connection,  (Bokhtiar et al., 2003; Goto and Nagata,  2000) showed that applied green manure plays an important role in increasing the total carbon content and bulk density of the soil,  which resulted in higher yield components. Straw manure and lupine green manure with NPK fertilizer resulted in longer spikes compared to similar CRs without  NPK fertilizer.

Applying organic and inorganic fertilizers together is very effective in plant productivity (Naik and Ballal, 1968; Yadav and Sharma, 1981; Bangar et al., 1994). We  also found that the fallow method helps to  restore the soil organic matter content into  the upper layers of the soil, which increase  the biological activity on the surface of the soil  and rehabilitates the activity of soil  microorganisms, which is reduced during the  

CONCLUSION 

It can be concluded that spike parameters were influenced by the crop rotations system. Application of organic fertilization methods with NPK fertilizer has a good effect on the length of the spike. Application of organic manure with chemical fertilizer had a  significantly better effect on the seed weight/spike than without chemical fertilizer in both analyzed years. Application of straw manure and green lupine manure with  

cultivation phase (Styger et al., 2006). In addition, applying straw manure besides using chemical fertilizers in CR VI resulted in the highest values of spike weight. Results also showed that using straw manure and lupine green manure recorded higher seed weight/spike besides chemical fertilizers,  than without chemical fertilizer in both of analyzed years, many researchers indicated that seed weight per spike is influenced by nutrient applications.

In this connection,  (Castagna et al., 1996; Thorup-Kristensen and Bertelsen, 1996; Granstedt and  Kjellenberg, 1997; Takunov and Yagovenko,  2000; Bradley et al., 2008; Gong et al., 2009;  Marino et al., 2009; Boumand et al., 2010)  noticed that nitrogen doses significantly influence the number of grains per spike,  consequently increased the seed weight/spike.

Several investigations indicated the positive effect of organic manure and chemical fertilizer use together, through increasing the soil organic carbon and NPK content therefore the crop productivity of soil and decreasing the damage that can be induced by chemical fertilizer using alone (Kaur et al., 2005; Chand et al., 2006; Murmu et al., 2013). In addition,  organic matter affects not only the yield by supplying nutrients but indirectly affects soil physical and chemical properties, too  (Darvish et al., 1995). 

chemical fertilizer resulted in a higher 1000  seed weight than without chemical fertilizer.  However, the farmyard manure could be able to produce the same result without chemical fertilizer, too. In addition, using organic fertilizer with chemical fertilizer increased the ratio between seed weight/spike to spike weight.

On the other hand, using straw manure without chemical fertilizer resulted in the lowest values of spike parameters in both analyzed years.  Moreover, applying a fallow system resulted in better rye spike parameters than using straw manure and lupine green manure weight/spike and spike length, spike weight,  1000 seed weight, and the ratio between seed weight/spike to spike weight. Finally,  seed weight/spike is strongly influenced by the other spike parameters i.e. spike length,  spike weight, and 1000 seed weight. 

Compliance with ethical standards 

without chemical fertilizer. Also, there was a  close positive correlation between the seed  The corresponding author declares that there is no conflict of interest regarding the publication of this manuscript. 

Funding 

This research did not receive any specific funding. 

REFERENCES 

Alam, F.; Majid, M. A.; Islam, M. J.  Improvement of soil and substitution of nitrogen with green-manure crops on follow-up sugarcane (Saccharum officinarum). Indian J. of Agric. Sci. 1997.  67(10), 455-458. 

Bandyopadhyay, K. K.; Misra, A. K.; Ghosh; P.  K.; Hati, K. M. Effect of integrated use of farmyard manure and chemical fertilizers on soil physical properties and productivity of soybean. Soil and Tillage Res. 2010,  110,115–125.  

Bangar, K. S.; Maini, A.; Sharma, S. R. Effect of fertilizer nitrogen and press mud cake on growth, yield and quality of sugarcane.  Crop Res. 1994, 8, 23–27. 

Barrios, E.; Cobo, J. G.; Idupulapati; M. R.;  Thomas, R. J.; Amézquita; E.; Jiménez, J. J.;  Rondón, M. A. Fallow management for soil fertility recovery in tropical Andean agroecosystems in Colombia. Agric.  Ecosyst. Environ. 2005, 110(1-2), 29-42. 

Bhardwaj, H. L.; Hamama, A. A.; Merrick, L. C.  Genotypic and environmental effects on lupin seed composition. Plant Foods Hum.  Nutr. 1998, 53:1–13. 

Bokhtiar, S. M.; Sakurai, K. Effects of organic manure and chemical fertilizer on soil fertility and productivity of plant and ratoon crops of sugarcane. Arch. Agron. Soil  Sci. 2005, 51(3), 325-334. 

Bokhtiar, S. M.; Gafur, M. A.; Rahman, A. B.  M. M. Effects of Crotalaria and Sesbania aculeata green manures and N fertilizer on soil fertility and the productivity of sugarcane. J. of Agric. Sci. Cambridge Univ. 140, 305–309.  

Bradley, E. F.; Kurt, D.Th.; Doo, H. M. Use of manure, compost, and cover crops to supplant crop residue carbon in corn stover removed cropping systems. Agron. J. 2008, 100(6),1703-17010. 

Broumand, P.; Rezaei, A.; Soleymani, A.;  Shahrajabian, M. H.; Noory, A. Influence of forage clipping and top dressing of nitrogen fertilizer on grain yield of cereal crops in dual purpose cultivation system. Res. on  Crops, 2010, 11(3), 603-613. 

Bushuk, W. Rye production and uses worldwide. Cereal Chem. 2001, 46(2), 70– 73. 

Castagna, R.; Minoia, C.; Porfiri, O.; Roccheti,  G. Nitrogen level and seeding rate effects on the performance of hulled wheats  (Triticum monococcum L., T. dicoccum Schubler and T. spelta L.) evaluated in contrasting agronomic environments.  Journal of Agron and Crop Sci. 1996, 176,  173-181. 

Chand, S.; Anwar, M.; Patra, D. D. Influence of long-term application of organic and inorganic fertilizer to build up soil fertility and nutrient uptake in mint‐mustard cropping sequence. Commun Soil Sci Plant  Anal. 2006, 37(1-2), 63-76. 

Darvish, O. H.; Persaud, N.; Martens, D. C.  Effect of long-term application of animal manure on physical properties of three soils. Plant Soil, 1995, 176:289–295. 

Dersch, G. and Bohm K. Effects of agronomic practices on the soil carbon storage potential in arable farming in Austria. Nutr.  Cycling Agroecosyst. 2001, 60, 49–55.

FAO. Food and Agriculture Organization of the United Nations, FAOSTAT, FAO  Statistics Division. 2020, November. 

Gill, H. S.; Meelu, O. P. Studies on the substitution of inorganic fertilizers with soil organic matter fractions and microbes under a wheat–maize cropping system in northern China. Geoderma, 2009, 149(3-4),  318-324. 

Goto, S.; Nagata, S. Effect of Clotararia,  sorgum and pampas grass incorporated as green manure on the yield of succeeding crops and soil physical and chemical properties. Soil Sci. Plant Nutr. 2000, 71(3), 337-344. 

Granstedt, A.; Kjellenberg, L. Long-term field experiment in Sweden: Effects of organic and inorganic fertilizers on soil fertility and  crop quality. In Proceedings of an  International Conference in Boston, Tufts  University, Agricultural Production and  Nutrition, Massachusetts, 1997, March 19- 21:1-14. 

Han, S. H.; An, J. Y.; Hwang, J., Kim, S. B., Park,  B. B. The effects of organic manure and chemical fertilizer on the growth and nutrient concentrations of yellow poplar  (Liriodendron tulipifera Lin.) in a nursery system. Forest Sci Technol. 2016, 13(3),  137-143. 

Hemalatha, S.; Chellamuthu, S. Impacts of long-term fertilization on soil nutritional quality under finger millet maize cropping sequences. J. Environ. Res. Develop. 7(4a),  1571-1576. 

Kätterer, T.; Bolinder, M. A.; Andrén, O.;  Kirchmann, H.; Menichetti, L. Roots contribute more to refractory soil organic matter than above-ground crop residues,  as revealed by a long-term field experiment. Agric. Ecosyst. Environ. 2011,  141(1-2), 184-192. 

Kaur, K.; Kapoor, K. K.; Gupta, A. P. Impact of organic manure with and without mineral fertilizers on soil chemical biological properties under tropical conditions.  Journal of Soil Sci. Plant Nutr. 2005, 168(1),  117–122. organic manure and their effect on soil fertility in rice-wheat rotation. Fertilizer  Res. 1982, 3,303-314. 

Gong, W.; Yan, X.; Wang, J.; Hu, T.; Gong, Y.  Long-term manure and fertilizer effects on  Kilic, H.; Yaǧbasanlar, T. The effect of drought stress on grain yield, yield components, and some quality traits of durum wheat  (Triticum turgidum ssp. durum) cultivars.  Notulae Botanicae Horti Agrobotanici Cluj Napoca, 2010, 38 (1),164-170. 

Kumar, V.; Mishra, D. Manurial value of press mud cake (Ganna-Khoi) Indian Farmers  Digest, 1992, 25,33 – 34. 

Kundu, S.; Ved, P.; Ghosh, B. N., Singh, R. D.;  Shrivastava, A. K. Quantitative relationship between annual carbon inputs and soil organic carbon build-up in Soybean  (Glycine max)-wheat (Triticum aestivum)  cropping sequence. In: Proceedings of the  2^nd International Agronomy, Congress, New  Delhi, India, 2002, November 26-30, 108- 110 pp. 

Liu, E.; Yan, C.; Mei, X.; He, W.; Bing, S. H.;  Ding, L.; Liu, Q.; Liu, S.; Fan, T. Long-term effect of chemical fertilizer, straw, and manure on soil chemical and biological properties in northwest China. Geoderma.  2010, 158(3-4), 173-180. 

Marino, S.; Tognetti, R.; Alvino, A. Crop yield and grain quality of emmer populations grown in central Italy, as affected by nitrogen fertilization. Eur. J. Agron. 2009,  31(4), 233-240. 

Murmu, K.; Swain, D. K.; Ghosh, B. C.  Comparative assessment of conventional and organic nutrient management on crop  growth and yield and soil fertility in tomato-sweet corn production system.  Aust. J. Crop Sci. 2013, 7(11), 1617–1626.  

Naik, B. N.; Ballal, D. K. Effect of association of organic matter with nitrogen fertilizer on availability and uptake of plant nutrients and the growth of the plant. II. Uptake of the nutrients and growth of the plant. J.  Indian Soc. Soil Sci. 1968, 16: 391–397.  

Nambiar, K.K.M. Soil fertility and crop productivity under long-term fertilizer use in India. Indian Council of Agricultural  Research, New Delhi, India. 1994. 

Nouraein, M. Elucidating seed yield and components in rye (Secale cereale L.) using discriminant function for selection in wheat. Heredity, 1970, 25, 383-392. 

Perry, M. W.; D’Antuono, M. F. Yield improvement and associated characteristics of some Australian spring wheat cultivars introduced between 1860  and 1982. Aust. J. Agric. Res. 1989, 40, 457- 472. 

Prasad, R. Cropping systems and sustainability of agriculture. Indian  Farming, 1996, 46, 39-45. 

Rabindra, B.; Gowda, S. N. S.; Gowda, H.  Effect of continuous use of nitrogenous fertilizers on soil physico-chemical  properties, yield and juice quality of sugarcane. Indian Sugar, 1990, 9, 843-845. 

Sánchez, P. Science in agroforestry. Agrofor.  Syst. 1995, 30, 5-55. 

Sayre, K. D.; Rajaram, S.; Fischer, R. A. Yield potential progress in short bread wheats in northwest Mexico. Crop Sci. 1997, 37,  3642. 

Snedecor, G. W.; Cochran, W. G. Statistical  methods. Seventh Edition. Ames Iowa:  Statistical Methods. 7^Th Ed. Iowa State  University Press, Iowa, USA., 1980, 507, pp. 

Styger, E.; Erick, C. M. F. Contributions of  managed fallows to soil fertility recovery.  Biol. Approaches to Sustainable Soil  Systems, 2006, 29, 426-437. 

Swarup, A. Emerging soil fertility management issues for sustainable crop production in the irrigated system. In: Swarup,  A., Reddy, D.D., Prasad, R.N. (Eds.), Long-term soil fertility management through integrated plant nutrient supply. Indian  Institute of Soil Sci. Bhopal, 1998, 54-68. 

Takunov, I. P.; Yagovenko, L. L. Yellow lupin (Lupinus luteus L.) as a green manure crop preceding winter rye (Secale cereale L.). In:  Santen, E. van; Wink, M.; Weissmann, S.; path and correlation analyses. Genet.  Resour. Crop Evol. 2019, 66, 1533-1542.

Parado, S. R.; Joshi, B. A. Correlations, path coefficients and the implication of Römer, P. Book chapter; Conference paper:  Lupin, an ancient crop for the new  millennium: Proceedings of the 9th  International Lupin Conference,  Klink/Muritz, Germany, 20-24 June, 1999.

Tejada, M.; Gonzalez, J. L.; Garcia-Martinez,  A. M.; Parrado, J. Effects of different green manures on soil biological properties and maize yield. Bioresour. Technol. 2008, 99,  1758-1767. 

Thorup-Kristensen.; Bertelsen, K. M. Green manure crops in organic vegetable production. In: Kristensen, N. H., Hoeg Jensen H. New Research in Organic  Agriculture. Proceedings from the 11^th Int.  Sci. IFOAM Conf. Copenhagen, 1996, 75-79 pp. 

Tian, G.; Kang, B. T.; Kolawole, G. O.; Idinoba,  P.; Salako, F. K. Long-term effects of fallow systems and lengths on crop production and soil fertility maintenance in West  Africa. Nutr. Cycl. Agroecosystems. 2005,  71, 139-150. 

Tukey, J. W. Exploratory data analysis.  Addison-Wesley, Reading, Statistical  Science, 1977, 18(3), 311-318. 

Yadav, R. L.; Sharma, R. K. Effect of nitrogen applied to plant cane crop of sugarcane on the yield and quality of subsequent ratoon crop. Indian J. Agric. Sci. 1983, 53: 38–43. 

Yaǧbasanlar, T.; Ozkan, H. Correlation and path coefficient analysis for ear characters in triticale under Mediterranean climatic conditions. J. Agron. Crop Sci. 1995, 174,  297-300.  

Zhichen, Y.; Yizhong, L.; Fengrong, Z.;  Xiaoping, X.; Mo, L. Comparative analysis of the effects of straw-returning and decomposed manure on paddy soil fertility betterment. Chinese Society of Agricultural  Engineering. 2008, 24(3), 214-218.